A 57-year-old man with a history of pulmonary asbestosis was incidentally found to have benign mesothelial hyperplasia of the peritoneum at hernia repair. Five months later he developed a Coombs positive haemolytic anaemia of the IgG-C3d type caused by non specific IgG antibodies. At that time no underlying cause for the anaemia was found. The anaemia responded to steroids, but remained steroid dependent. Six months after the diagnosis of the anaemia, a malignant peritoneal mesothelioma was found at laparotomy. The association between malignant mesothelioma and autoimmune haemolytic anaemia has been reported on one previous occasion. The description of a second case suggests that the association is not purely coincidental and that malignant mesothelioma should be added to the list of solid tumours that can be associated with autoimmune haemolytic anaemia. The finding of red blood cells coated with IgG and C3d in this as well as in other cases adds further evidence to the hypothesis that a quinidine type mechanism of haemolysis might be responsible for Coombs positive haemolytic anaemia associated with solid tumours.