AIM: To evaluate the rote of computed tomography (CT) after herniography in the diagnosis and management of primary and recurrent groin hernias not detectable on clinical examination. MATERIAL AND METHODS: Fifty-one patients underwent CT post-herniography over a 6-year period for suspected primary or recurrent inguinal hernia. The herniography and post-herniography CT findings were retrospectively compared with clinical and surgical follow-up. Statistical analysis was performed to assess the role of herniography and CT post-herniography in the primary and recurrent groups. RESULTS: Of the 51 patients investigated for occult inguinal hernia, 19 had previous hernia repair with possible recurrence. The most common symptom at presentation was groin pain or discomfort (84%). Seventy-five percent in the primary group and 84% in the recurrent group had no findings on herniography or CT. Nine percent in the primary group and 16% in the recurrent group had hernias diagnosed by herniography. CT did not enhance the detection of hernia. Sensitivity for herniography and CT herniography in the primary groin hernia group was 75% as against specificity, which was 100 and 90%, respectively. For the recurrent groin hernias, sensitivity was 60% for herniography and 40% for CT herniography and specificity 100% for both. CONCLUSION: CT performed post-herniography did not provide any benefit over performing herniography alone in the diagnosis of occult primary or recurrent inguinal hernias. (C) 2005 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.