diff --git a/cg/cli/add.py b/cg/cli/add.py
index ce0c8cf505..86a097a0bf 100644
--- a/cg/cli/add.py
+++ b/cg/cli/add.py
@@ -337,12 +337,20 @@ def link_sample_to_case(
             LOG.error(f"{mother_id}: mother not found")
             raise click.Abort
 
+        if mother.sex != Sex.FEMALE:
+            LOG.error(f"{mother_id}: mother is not {Sex.FEMALE}")
+            raise click.Abort
+
     if father_id:
         father: Sample = status_db.get_sample_by_internal_id(internal_id=father_id)
         if father is None:
             LOG.error(f"{father_id}: father not found")
             raise click.Abort
 
+        if father.sex != Sex.MALE:
+            LOG.error(f"{father_id}: father is not {Sex.MALE}")
+            raise click.Abort
+
     new_record: CaseSample = status_db.relate_sample(
         case=case_obj, sample=sample, status=status, mother=mother, father=father
     )
diff --git a/tests/cli/add/test_cli_add_relationship.py b/tests/cli/add/test_cli_add_relationship.py
index c11a33c3bb..bc0b960964 100644
--- a/tests/cli/add/test_cli_add_relationship.py
+++ b/tests/cli/add/test_cli_add_relationship.py
@@ -3,6 +3,7 @@
 from click.testing import CliRunner
 
 from cg.cli.add import add
+from cg.constants import EXIT_FAIL
 from cg.constants.subject import Sex
 from cg.models.cg_config import CGConfig
 from cg.store.models import CaseSample
@@ -257,3 +258,75 @@ def test_add_relationship_bad_father(
     # THEN it should not be added
     assert result.exit_code == 1
     assert disk_store._get_query(table=CaseSample).count() == 0
+
+
+def test_add_relationship_mother_not_female(
+    cli_runner: CliRunner, base_context: CGConfig, helpers: StoreHelpers
+):
+    """Test to add a relationship where the mother is not female"""
+    # GIVEN a database with a sample, a case, and a male sample labeled as mother
+    disk_store: Store = base_context.status_db
+    sample: Sample = helpers.add_sample(disk_store)
+    sample_id: str = sample.internal_id
+
+    male_mother: Sample = helpers.add_sample(disk_store, sex=Sex.MALE, name="mother")
+    male_mother_id: str = male_mother.internal_id
+
+    case: Case = helpers.add_case(disk_store)
+    case_id: str = case.internal_id
+    status = "affected"
+
+    # WHEN adding a relationship with a male mother
+    result = cli_runner.invoke(
+        add,
+        [
+            "relationship",
+            case_id,
+            sample_id,
+            "-s",
+            status,
+            "-m",
+            male_mother_id,
+        ],
+        obj=base_context,
+    )
+
+    # THEN it should fail because the mother is not female
+    assert result.exit_code == EXIT_FAIL
+    assert disk_store._get_query(table=CaseSample).count() == 0
+
+
+def test_add_relationship_father_not_male(
+    cli_runner: CliRunner, base_context: CGConfig, helpers: StoreHelpers
+):
+    """Test to add a relationship where the father is not male"""
+    # GIVEN a database with a sample, a case, and a female sample labeled as father
+    disk_store: Store = base_context.status_db
+    sample: Sample = helpers.add_sample(disk_store)
+    sample_id: str = sample.internal_id
+
+    female_father: Sample = helpers.add_sample(disk_store, sex=Sex.FEMALE, name="father")
+    female_father_id: str = female_father.internal_id
+
+    case: Case = helpers.add_case(disk_store)
+    case_id: str = case.internal_id
+    status = "affected"
+
+    # WHEN adding a relationship with a female father
+    result = cli_runner.invoke(
+        add,
+        [
+            "relationship",
+            case_id,
+            sample_id,
+            "-s",
+            status,
+            "-f",
+            female_father_id,
+        ],
+        obj=base_context,
+    )
+
+    # THEN it should fail because the father is not male
+    assert result.exit_code == EXIT_FAIL
+    assert disk_store._get_query(table=CaseSample).count() == 0