A case is presented of caecal tuberculosis coexisting with adenocarcinoma at the same site, unusually presenting as a right iliac fossa abscess. The relevant literature on 61 previously reported patients with coexisting tuberculosis and colonic carcinoma is reviewed. The patient was 81-years-old, female with a tender swelling in the right iliac fossa. Following examination by ultrasound, laparotomy was undertaken which revealed a large abscess cavity contaminated by Mycobacterium tuberculosis. Although anti-tuberculosis treatment was given, there was a persistent purulent discharge from the wound, so a new ultrasound, computed tomography scan and barium enema were arranged. These could not clearly differentiate between ileocaecal tuberculosis and carcinoma. A second laparotomy showed that there was an underlying adenocarcinoma. Although rare, the coexistence of colonic tuberculosis with carcinoma should be seriously considered especially in patients who fail to respond to anti-tuberculosis treatment. A definitive diagnosis can be established only by histological examination.