diff --git a/src/NHibernate.Test/App.config b/src/NHibernate.Test/App.config
index bd345778701..356ed814805 100644
--- a/src/NHibernate.Test/App.config
+++ b/src/NHibernate.Test/App.config
@@ -51,6 +51,8 @@
 			<property name="format_sql">true</property>
 			<property name="show_sql">false</property>
 			<property name="command_timeout">444</property>
+
+			<property name="default_flush_mode">Commit</property>
 			
 		</session-factory>
 	</hibernate-configuration>
diff --git a/src/NHibernate.Test/CfgTest/DefaultFlushModeFixture.cs b/src/NHibernate.Test/CfgTest/DefaultFlushModeFixture.cs
new file mode 100644
index 00000000000..4a72d2bbae9
--- /dev/null
+++ b/src/NHibernate.Test/CfgTest/DefaultFlushModeFixture.cs
@@ -0,0 +1,82 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using NHibernate.Cfg;
+using NUnit.Framework;
+
+namespace NHibernate.Test.CfgTest
+{
+	[TestFixture]
+	public class DefaultFlushModeFixture
+	{
+		[Test]
+		public void CanSetDefaultFlushModeThroughXmlConfiguration()
+		{
+			var cfg = new Configuration().Configure();
+
+			using (var sessionFactory = cfg.BuildSessionFactory())
+			{
+				using (var session = sessionFactory.OpenSession())
+				{
+					Assert.AreEqual(session.FlushMode, FlushMode.Commit);
+				}
+			}
+		}
+
+		[Test]
+		public void CanSetDefaultFlushModeThroughStandardConfiguration()
+		{
+			var cfg = new Configuration().Configure();
+			cfg.Properties[Environment.DefaultFlushMode] = FlushMode.Always.ToString();
+
+			using (var sessionFactory = cfg.BuildSessionFactory())
+			{
+				using (var session = sessionFactory.OpenSession())
+				{
+					Assert.AreEqual(session.FlushMode, FlushMode.Always);
+				}
+			}
+
+			cfg.Properties[Environment.DefaultFlushMode] = FlushMode.Commit.ToString();
+
+			using (var sessionFactory = cfg.BuildSessionFactory())
+			{
+				using (var session = sessionFactory.OpenSession())
+				{
+					Assert.AreEqual(session.FlushMode, FlushMode.Commit);
+				}
+			}
+		}
+
+		[Test]
+		public void CanSetDefaultFlushModeThroughLoquaciousConfiguration()
+		{
+			var cfg = new Configuration()
+				.Configure();
+
+			cfg
+				.SessionFactory()
+				.DefaultFlushMode(FlushMode.Always);
+
+			using (var sessionFactory = cfg.BuildSessionFactory())
+			{
+				using (var session = sessionFactory.OpenSession())
+				{
+					Assert.AreEqual(session.FlushMode, FlushMode.Always);
+				}
+			}
+
+			cfg.Configure()
+				.SessionFactory()
+				.DefaultFlushMode(FlushMode.Commit);
+
+			using (var sessionFactory = cfg.BuildSessionFactory())
+			{
+				using (var session = sessionFactory.OpenSession())
+				{
+					Assert.AreEqual(session.FlushMode, FlushMode.Commit);
+				}
+			}
+		}
+	}
+}
diff --git a/src/NHibernate.Test/NHibernate.Test.csproj b/src/NHibernate.Test/NHibernate.Test.csproj
index 44b9c69daa0..a8e781f928e 100644
--- a/src/NHibernate.Test/NHibernate.Test.csproj
+++ b/src/NHibernate.Test/NHibernate.Test.csproj
@@ -166,6 +166,7 @@
     <Compile Include="CfgTest\ConfigurationSchemaFixture.cs" />
     <Compile Include="CfgTest\ConfigurationSerializationTests.cs" />
     <Compile Include="CfgTest\CustomBytecodeProviderTest.cs" />
+    <Compile Include="CfgTest\DefaultFlushModeFixture.cs" />
     <Compile Include="CfgTest\DefaultNsAssmFixture.cs" />
     <Compile Include="CfgTest\EntityCacheUsageParserFixture.cs" />
     <Compile Include="CfgTest\HbmOrderingFixture.cs" />
diff --git a/src/NHibernate/Cfg/Environment.cs b/src/NHibernate/Cfg/Environment.cs
index bae74bd511a..ed597208cad 100644
--- a/src/NHibernate/Cfg/Environment.cs
+++ b/src/NHibernate/Cfg/Environment.cs
@@ -90,6 +90,9 @@ public static string Version
 		/// <summary>The EntityMode in which set the Session opened from the SessionFactory.</summary>
 		public const string DefaultEntityMode = "default_entity_mode";
 
+		/// Implementation of NH-3619 - Make default value of FlushMode configurable
+		public const string DefaultFlushMode = "default_flush_mode";
+
 		/// <summary>
 		/// When using an enhanced id generator and pooled optimizers (<see cref="NHibernate.Id.Enhanced.IOptimizer"/>),
 		/// prefer interpreting the database value as the lower (lo) boundary. The default is to interpret it as the high boundary.
diff --git a/src/NHibernate/Cfg/Loquacious/FluentSessionFactoryConfiguration.cs b/src/NHibernate/Cfg/Loquacious/FluentSessionFactoryConfiguration.cs
index f5dc921c471..d53ad96226c 100644
--- a/src/NHibernate/Cfg/Loquacious/FluentSessionFactoryConfiguration.cs
+++ b/src/NHibernate/Cfg/Loquacious/FluentSessionFactoryConfiguration.cs
@@ -47,6 +47,12 @@ public IFluentSessionFactoryConfiguration Using(EntityMode entityMode)
 			return this;
 		}
 
+		public IFluentSessionFactoryConfiguration DefaultFlushMode(FlushMode flushMode)
+		{
+			configuration.SetProperty(Environment.DefaultFlushMode, flushMode.ToString());
+			return this;
+		}
+
 		public IFluentSessionFactoryConfiguration ParsingHqlThrough<TQueryTranslator>()
 			where TQueryTranslator : IQueryTranslatorFactory
 		{
diff --git a/src/NHibernate/Cfg/Loquacious/IFluentSessionFactoryConfiguration.cs b/src/NHibernate/Cfg/Loquacious/IFluentSessionFactoryConfiguration.cs
index 23ac2c3abe4..c16897b84a5 100644
--- a/src/NHibernate/Cfg/Loquacious/IFluentSessionFactoryConfiguration.cs
+++ b/src/NHibernate/Cfg/Loquacious/IFluentSessionFactoryConfiguration.cs
@@ -26,6 +26,8 @@ public interface IFluentSessionFactoryConfiguration
 
 		IFluentSessionFactoryConfiguration GenerateStatistics();
 		IFluentSessionFactoryConfiguration Using(EntityMode entityMode);
+		IFluentSessionFactoryConfiguration DefaultFlushMode(FlushMode flushMode);
+
 		IFluentSessionFactoryConfiguration ParsingHqlThrough<TQueryTranslator>() where TQueryTranslator : IQueryTranslatorFactory;
 		IFluentSessionFactoryConfiguration ParsingLinqThrough<TQueryProvider>() where TQueryProvider : INhQueryProvider;
 
diff --git a/src/NHibernate/Cfg/Settings.cs b/src/NHibernate/Cfg/Settings.cs
index 5856837f5f3..f2057651d34 100644
--- a/src/NHibernate/Cfg/Settings.cs
+++ b/src/NHibernate/Cfg/Settings.cs
@@ -110,6 +110,8 @@ public Settings()
 
 		public bool IsOrderInsertsEnabled { get; internal set; }
 
+		public FlushMode DefaultFlushMode { get; internal set; }
+
 		public EntityMode DefaultEntityMode { get; internal set; }
 
 		public bool IsDataDefinitionImplicitCommit { get; internal set; }
diff --git a/src/NHibernate/Cfg/SettingsFactory.cs b/src/NHibernate/Cfg/SettingsFactory.cs
index f2fc0fea68f..7e852fde5c7 100644
--- a/src/NHibernate/Cfg/SettingsFactory.cs
+++ b/src/NHibernate/Cfg/SettingsFactory.cs
@@ -259,6 +259,11 @@ public Settings BuildSettings(IDictionary<string, string> properties)
 				}
 			}
 
+			//NH-3619
+			FlushMode defaultFlushMode = (FlushMode) Enum.Parse(typeof(FlushMode), PropertiesHelper.GetString(Environment.DefaultFlushMode, properties, FlushMode.Unspecified.ToString()), false);
+			log.Info("Default flush mode: " + defaultFlushMode);
+			settings.DefaultFlushMode = defaultFlushMode;
+
 			EntityMode defaultEntityMode =
 				EntityModeHelper.Parse(PropertiesHelper.GetString(Environment.DefaultEntityMode, properties, "poco"));
 			log.Info("Default entity-mode: " + defaultEntityMode);
diff --git a/src/NHibernate/Impl/SessionFactoryImpl.cs b/src/NHibernate/Impl/SessionFactoryImpl.cs
index 6ece3cf91f7..ac08d74c2e5 100644
--- a/src/NHibernate/Impl/SessionFactoryImpl.cs
+++ b/src/NHibernate/Impl/SessionFactoryImpl.cs
@@ -497,7 +497,7 @@ public ISession OpenSession(IDbConnection connection, bool flushBeforeCompletion
 			return
 				new SessionImpl(connection, this, true, settings.CacheProvider.NextTimestamp(), interceptor,
 								settings.DefaultEntityMode, flushBeforeCompletionEnabled, autoCloseSessionEnabled,
-								isInterceptorsBeforeTransactionCompletionIgnoreExceptionsEnabled, connectionReleaseMode);
+								isInterceptorsBeforeTransactionCompletionIgnoreExceptionsEnabled, connectionReleaseMode, settings.DefaultFlushMode);
 		}
 
 		public IEntityPersister GetEntityPersister(string entityName)
@@ -1215,7 +1215,8 @@ private SessionImpl OpenSession(IDbConnection connection, bool autoClose, long t
 			SessionImpl session = new SessionImpl(connection, this, autoClose, timestamp, sessionLocalInterceptor ?? interceptor,
 												  settings.DefaultEntityMode, settings.IsFlushBeforeCompletionEnabled,
 												  settings.IsAutoCloseSessionEnabled, isInterceptorsBeforeTransactionCompletionIgnoreExceptionsEnabled,
-												  settings.ConnectionReleaseMode);
+												  settings.ConnectionReleaseMode, settings.DefaultFlushMode);
+
 			if (sessionLocalInterceptor != null)
 			{
 				// NH specific feature
diff --git a/src/NHibernate/Impl/SessionImpl.cs b/src/NHibernate/Impl/SessionImpl.cs
index 71d90f2f7be..885399a2536 100644
--- a/src/NHibernate/Impl/SessionImpl.cs
+++ b/src/NHibernate/Impl/SessionImpl.cs
@@ -215,7 +215,8 @@ internal SessionImpl(
 			bool flushBeforeCompletionEnabled,
 			bool autoCloseSessionEnabled,
 			bool ignoreExceptionBeforeTransactionCompletion,
-			ConnectionReleaseMode connectionReleaseMode)
+			ConnectionReleaseMode connectionReleaseMode,
+			FlushMode defaultFlushMode)
 			: base(factory)
 		{
 			using (new SessionIdLoggingContext(SessionId))
@@ -235,6 +236,7 @@ internal SessionImpl(
 				this.connectionReleaseMode = connectionReleaseMode;
 				this.ignoreExceptionBeforeTransactionCompletion = ignoreExceptionBeforeTransactionCompletion;
 				connectionManager = new ConnectionManager(this, connection, connectionReleaseMode, interceptor);
+				this.flushMode = defaultFlushMode;
 
 				if (factory.Statistics.IsStatisticsEnabled)
 				{
diff --git a/src/NHibernate/nhibernate-configuration.xsd b/src/NHibernate/nhibernate-configuration.xsd
index d1942c3e3a4..2b74d4dd35b 100644
--- a/src/NHibernate/nhibernate-configuration.xsd
+++ b/src/NHibernate/nhibernate-configuration.xsd
@@ -111,6 +111,7 @@
 								<xs:enumeration value="adonet.factory_class" />
 								<xs:enumeration value="default_batch_fetch_size" />
 								<xs:enumeration value="default_entity_mode" />
+								<xs:enumeration value="default_flush_mode" />
 								<xs:enumeration value="use_sql_comments" />
 								<xs:enumeration value="format_sql" />
 								<xs:enumeration value="collectiontype.factory_class" />