A case of alpha-fetoprotein production by a uterine malignant mixed müllerian tumour is described. The patient was a 68 year old woman who developed intraabdominal recurrence of a stage 1 uterine tumour which had been treated surgically seven years previously. Her serum alpha-fetoprotein was raised at 21,000 micrograms/l (normal < 10 micrograms/l) and staining with immunoperoxidase confirmed that the tumour was the site of alpha-fetoprotein production. The patient was treated with combination chemotherapy but died two weeks after the first course. This is believed to be only the second such case reported.