diff --git a/pydantic_settings/sources/providers/aws.py b/pydantic_settings/sources/providers/aws.py
index dc5c0cd0..c1004ec5 100644
--- a/pydantic_settings/sources/providers/aws.py
+++ b/pydantic_settings/sources/providers/aws.py
@@ -4,6 +4,7 @@
 from collections.abc import Mapping
 from typing import TYPE_CHECKING, Optional
 
+from ..utils import parse_env_vars
 from .env import EnvSettingsSource
 
 if TYPE_CHECKING:
@@ -36,6 +37,7 @@ def __init__(
         settings_cls: type[BaseSettings],
         secret_id: str,
         region_name: str | None = None,
+        case_sensitive: bool | None = True,
         env_prefix: str | None = None,
         env_parse_none_str: str | None = None,
         env_parse_enums: bool | None = None,
@@ -45,7 +47,7 @@ def __init__(
         self._secret_id = secret_id
         super().__init__(
             settings_cls,
-            case_sensitive=True,
+            case_sensitive=case_sensitive,
             env_prefix=env_prefix,
             env_nested_delimiter='--',
             env_ignore_empty=False,
@@ -56,7 +58,12 @@ def __init__(
     def _load_env_vars(self) -> Mapping[str, Optional[str]]:
         response = self._secretsmanager_client.get_secret_value(SecretId=self._secret_id)  # type: ignore
 
-        return json.loads(response['SecretString'])
+        return parse_env_vars(
+            json.loads(response['SecretString']),
+            self.case_sensitive,
+            self.env_ignore_empty,
+            self.env_parse_none_str,
+        )
 
     def __repr__(self) -> str:
         return (
diff --git a/tests/test_source_aws_secrets_manager.py b/tests/test_source_aws_secrets_manager.py
index 46160070..c68aa928 100644
--- a/tests/test_source_aws_secrets_manager.py
+++ b/tests/test_source_aws_secrets_manager.py
@@ -88,6 +88,43 @@ class AWSSecretsManagerSettings(BaseSettings):
         assert settings['SqlServerUser'] == 'test-user'
         assert settings['SqlServer']['Password'] == 'test-password'
 
+    @mock_aws
+    def test_secret_manager_case_insensitive_success(self) -> None:
+        """Test secret manager getitem case insensitive success."""
+
+        class SqlServer(BaseModel):
+            password: str = Field(..., alias='Password')
+
+        class AWSSecretsManagerSettings(BaseSettings):
+            """AWSSecretsManager settings."""
+
+            sql_server_user: str
+            sql_server: SqlServer
+
+            @classmethod
+            def settings_customise_sources(
+                cls,
+                settings_cls: type[BaseSettings],
+                init_settings: PydanticBaseSettingsSource,
+                env_settings: PydanticBaseSettingsSource,
+                dotenv_settings: PydanticBaseSettingsSource,
+                file_secret_settings: PydanticBaseSettingsSource,
+            ) -> tuple[PydanticBaseSettingsSource, ...]:
+                return (AWSSecretsManagerSettingsSource(settings_cls, 'test-secret', case_sensitive=False),)
+
+        secret_data = {
+            'SQL_SERVER_USER': 'test-user',
+            'SQL_SERVER--PASSWORD': 'test-password',
+        }
+
+        client = boto3.client('secretsmanager')
+        client.create_secret(Name='test-secret', SecretString=json.dumps(secret_data))
+
+        settings = AWSSecretsManagerSettings()  # type: ignore
+
+        assert settings.sql_server_user == 'test-user'
+        assert settings.sql_server.password == 'test-password'
+
     @mock_aws
     def test_aws_secrets_manager_settings_source(self) -> None:
         """Test AWSSecretsManagerSettingsSource."""