We report a case of primary ileal carcinoma in a young woman, which was diagnosed definitively before operation. A 29-year-old woman presented with abdominal pain, diarrhoea and bloody stools. Colonoscopic and radiographic studies revealed that there was a 7.5 x 7 cm tumour (well-differentiated adenocarcinoma) at the terminal ileum, forming an ulcerated lesion at the centre. The tumour had invaded the caecum, the right urinary tract, the right ovary and a portion of the sigmoid colon. Fifty-three cases of primary ileal carcinoma were reported in Japan between 1982 and 1994 and their clinical features are reviewed herein.