diff --git a/vulnerabilities/import_runner.py b/vulnerabilities/import_runner.py
index c57e0eebd..b4716fe41 100644
--- a/vulnerabilities/import_runner.py
+++ b/vulnerabilities/import_runner.py
@@ -39,6 +39,7 @@ def run(self) -> None:
         """
         importer_name = self.importer_class.qualified_name
         importer_class = self.importer_class
+        Advisory.objects.filter(created_by=importer_name).delete()
         logger.info(f"Starting import for {importer_name}")
         advisory_datas = importer_class().advisory_data()
         count = process_advisories(advisory_datas=advisory_datas, importer_name=importer_name)
diff --git a/vulnerabilities/tests/test_deletion_of_advisories.py b/vulnerabilities/tests/test_deletion_of_advisories.py
new file mode 100644
index 000000000..2c86a8126
--- /dev/null
+++ b/vulnerabilities/tests/test_deletion_of_advisories.py
@@ -0,0 +1,47 @@
+import os
+from unittest import mock
+
+import pytest
+
+from vulnerabilities.import_runner import ImportRunner
+from vulnerabilities.importers.nginx import NginxImporter
+from vulnerabilities.improve_runner import ImproveRunner
+from vulnerabilities.improvers.default import DefaultImprover
+from vulnerabilities.models import Package
+from vulnerabilities.models import Vulnerability
+from vulnerabilities.models import VulnerabilityReference
+
+BASE_DIR = os.path.dirname(os.path.abspath(__file__))
+TEST_DATA = os.path.join(BASE_DIR, "test_data", "nginx")
+
+
+@pytest.mark.django_db
+@mock.patch("vulnerabilities.importers.nginx.NginxImporter.fetch")
+def test_deletion_of_advisories(fetch):
+    """Test that the deletion of advisories works as expected."""
+    with open(os.path.join(TEST_DATA, "security_advisories.html")) as f:
+        fetch.return_value = f.read()
+
+    ImportRunner(NginxImporter).run()
+    ImproveRunner(DefaultImprover).run()
+    packages = Package.objects.all().only("id")
+    packages_before_deletion = [int(package.id) for package in packages]
+    vulnerabilities = Vulnerability.objects.all().only("vulnerability_id")
+    vulnerabilities_before_deletion = [
+        str(vulnerability.vulnerability_id) for vulnerability in vulnerabilities
+    ]
+    references = VulnerabilityReference.objects.all().only("id")
+    references_before_deletion = [int(reference.id) for reference in references]
+    ImportRunner(NginxImporter).run()
+    ImproveRunner(DefaultImprover).run()
+    packages = Package.objects.all().only("id")
+    packages_after_deletion = [int(package.id) for package in packages]
+    vulnerabilities = Vulnerability.objects.all().only("vulnerability_id")
+    vulnerabilities_after_deletion = [
+        str(vulnerability.vulnerability_id) for vulnerability in vulnerabilities
+    ]
+    references = VulnerabilityReference.objects.all().only("id")
+    references_after_deletion = [int(reference.id) for reference in references]
+    assert packages_before_deletion == packages_after_deletion
+    assert vulnerabilities_before_deletion == vulnerabilities_after_deletion
+    assert references_before_deletion == references_after_deletion