diff --git a/tests/test_detector_named_entity.py b/tests/test_detector_named_entity.py
new file mode 100644
index 00000000..c23f968d
--- /dev/null
+++ b/tests/test_detector_named_entity.py
@@ -0,0 +1,67 @@
+import unittest
+
+from scrubadub.detectors import NamedEntityDetector
+from scrubadub.filth import NameFilth, OrganizationFilth, NamedEntityFilth
+import scrubadub
+
+from base import BaseTestCase
+
+
+class NamedEntityTestCase(unittest.TestCase, BaseTestCase):
+    """
+    Tests whether the detector is performing correctly from a function point of view.
+    For accuracy tests use .benchmark_accuracy instead
+    """
+
+    def setUp(self):
+        self.detector = NamedEntityDetector()
+
+    def _assert_filth_type_and_pos(self, doc_list, beg_end_list, filth_class):
+        doc_names = [str(x) for x in range(len(doc_list))]
+
+        filth_list = list(self.detector.iter_filth_documents(doc_names, doc_list))
+
+        for filth, beg_end in zip(filth_list, beg_end_list):
+            self.assertIsInstance(filth, filth_class)
+            self.assertEqual((filth.beg, filth.end), beg_end)
+
+    def test_names(self):
+        doc_list = ["John is a cat",
+                    "When was Maria born?",
+                    "john is a cat",
+                    "when was maria born"]
+        beg_end_list = [(0, 4),
+                        (9, 14),
+                        (0, 4),
+                        (9, 14)]
+
+        self._assert_filth_type_and_pos(doc_list, beg_end_list, NameFilth)
+
+    def test_organisations(self):
+        doc_list = ["She started working for Apple this year",
+                    "But used to work for Google"]
+        beg_end_list = [(24, 30),
+                        (21, 27)]
+
+        self._assert_filth_type_and_pos(doc_list, beg_end_list, OrganizationFilth)
+
+    def test_other_entity(self):
+        self.detector.named_entities = {"GPE"}
+        doc_list = ["London is a city in England"]
+        beg_end_list = [(0, 6),
+                        (20, 27)]
+
+        self._assert_filth_type_and_pos(doc_list, beg_end_list, NamedEntityFilth)
+
+    def test_wrong_model(self):
+        """Test that it raises an error if user inputs invalid spacy model"""
+        with self.assertRaises(SystemExit):
+            NamedEntityDetector(model='not_a_valid_spacy_model')
+
+    def test_iter_filth(self):
+        doc = "John is a cat"
+
+        output_iter_docs = list(self.detector.iter_filth_documents(doc_list=[doc], doc_names=["0"]))
+        output_iter = list(self.detector.iter_filth(text=doc, document_name="0"))
+
+        self.assertListEqual(output_iter, output_iter_docs)