diff --git a/src/sentry/release_health/base.py b/src/sentry/release_health/base.py
index 9dde179b53c106..e0b30fee3d6a64 100644
--- a/src/sentry/release_health/base.py
+++ b/src/sentry/release_health/base.py
@@ -38,6 +38,7 @@
     "foreground_anr_rate()",
     "unhandled_rate(session)",
     "unhandled_rate(user)",
+    "unhealthy_rate(session)",
 ]
 
 GroupByFieldName = Literal[
diff --git a/src/sentry/release_health/metrics_sessions_v2.py b/src/sentry/release_health/metrics_sessions_v2.py
index 869a7e66cd48e7..ff251a8eacd667 100644
--- a/src/sentry/release_health/metrics_sessions_v2.py
+++ b/src/sentry/release_health/metrics_sessions_v2.py
@@ -347,6 +347,7 @@ class SimpleForwardingField(Field):
         "foreground_anr_rate()": SessionMRI.FOREGROUND_ANR_RATE,
         "unhandled_rate(session)": SessionMRI.UNHANDLED_RATE,
         "unhandled_rate(user)": SessionMRI.UNHANDLED_USER_RATE,
+        "unhealthy_rate(session)": SessionMRI.UNHEALTHY_RATE,
     }
 
     def __init__(self, name: str, raw_groupby: Sequence[str], status_filter: StatusFilter):
@@ -387,6 +388,7 @@ def _get_metric_fields(
     "foreground_anr_rate()": SimpleForwardingField,
     "unhandled_rate(session)": SimpleForwardingField,
     "unhandled_rate(user)": SimpleForwardingField,
+    "unhealthy_rate(session)": SimpleForwardingField,
 }
 PREFLIGHT_QUERY_COLUMNS = {"release.timestamp"}
 VirtualOrderByName = Literal["release.timestamp"]
diff --git a/src/sentry/snuba/metrics/fields/base.py b/src/sentry/snuba/metrics/fields/base.py
index 404c2dd9317bca..a23f1ec6e08fc2 100644
--- a/src/sentry/snuba/metrics/fields/base.py
+++ b/src/sentry/snuba/metrics/fields/base.py
@@ -1587,6 +1587,15 @@ def generate_where_statements(
             unit="sessions",
             post_query_func=lambda init, errored: max(0, init - errored),
         ),
+        CompositeEntityDerivedMetric(
+            metric_mri=SessionMRI.UNHEALTHY_RATE.value,
+            metrics=[
+                SessionMRI.ALL.value,
+                SessionMRI.ERRORED_ALL.value,
+            ],
+            unit="percentage",
+            post_query_func=lambda all, errored_all: (max(0, errored_all / all) if all else 0),
+        ),
         SingularEntityDerivedMetric(
             metric_mri=SessionMRI.HEALTHY_USER.value,
             metrics=[
diff --git a/src/sentry/snuba/metrics/naming_layer/mri.py b/src/sentry/snuba/metrics/naming_layer/mri.py
index b19ef312ef3f95..96a07ef45362f1 100644
--- a/src/sentry/snuba/metrics/naming_layer/mri.py
+++ b/src/sentry/snuba/metrics/naming_layer/mri.py
@@ -82,6 +82,7 @@ class SessionMRI(Enum):
     UNHANDLED_RATE = "e:sessions/unhandled_rate@ratio"  # unhandled, does not include crashed
     CRASH_RATE = "e:sessions/crash_rate@ratio"
     CRASH_FREE_RATE = "e:sessions/crash_free_rate@ratio"  # includes handled and unhandled
+    UNHEALTHY_RATE = "e:sessions/unhealthy_rate@ratio"
     ALL_USER = "e:sessions/user.all@none"
     HEALTHY_USER = "e:sessions/user.healthy@none"
     ERRORED_USER = "e:sessions/user.errored@none"
diff --git a/tests/snuba/api/endpoints/test_organization_sessions.py b/tests/snuba/api/endpoints/test_organization_sessions.py
index a70dc64d68339d..1ec1e76467bb09 100644
--- a/tests/snuba/api/endpoints/test_organization_sessions.py
+++ b/tests/snuba/api/endpoints/test_organization_sessions.py
@@ -1823,6 +1823,62 @@ def req(**kwargs):
             },
         ]
 
+    @freeze_time(MOCK_DATETIME)
+    def test_unhealthy_rate(self) -> None:
+        default_request = {
+            "project": [-1],
+            "statsPeriod": "1d",
+            "interval": "1d",
+            "field": ["unhealthy_rate(session)"],
+        }
+
+        def req(**kwargs):
+            return self.do_request(dict(default_request, **kwargs))
+
+        # 1 - filter session.status
+        response = req(
+            query="session.status:[abnormal,crashed]",
+        )
+        assert response.status_code == 400, response.content
+        assert response.data == {
+            "detail": "Cannot filter field unhealthy_rate(session) by session.status"
+        }
+
+        # 2 - group by session.status
+        response = req(
+            groupBy="session.status",
+        )
+        assert response.status_code == 400, response.content
+        assert response.data == {
+            "detail": "Cannot group field unhealthy_rate(session) by session.status"
+        }
+
+        # 3 - fetch foo@1.0.0 release
+        response = req(
+            field=[
+                "unhealthy_rate(session)",
+                "sum(session)",
+            ],
+            groupBy=["release", "environment"],
+            query="release:foo@1.0.0",
+        )
+        assert response.status_code == 200, response.content
+        group = response.data["groups"][0]
+        assert group["totals"]["sum(session)"] == 8
+        assert group["totals"]["unhealthy_rate(session)"] == pytest.approx(0.5)
+
+        # 4 - fetch all
+        response = req(
+            field=[
+                "unhealthy_rate(session)",
+                "sum(session)",
+            ],
+        )
+        assert response.status_code == 200, response.content
+        group = response.data["groups"][0]
+        assert group["totals"]["sum(session)"] == 11
+        assert group["totals"]["unhealthy_rate(session)"] == pytest.approx(5 / 11)
+
     @freeze_time(MOCK_DATETIME)
     def test_pagination(self) -> None:
         def do_request(cursor):