Case presentation of a 35-year-old patient with a history of chronic colitis of 16 years duration. Crohn's disease in this patient involved the entire colon without skip lesions and without terminal ileitis. The course was complicated by recurrent erythema nodosum and wandering arthritis as well as sclerosing cholangitis and multifocal adenocarcinoma of the large bowel. Sclerosing cholangitis is a rare condition in Crohn's disease (1,8) whereas pericholangitis in liver biopsy specimen was diagnosed in prospective studies in 8 (7) to 30 (2) per cent. The same is true for carcinomas complicating granulomatous enterocolitis. In a recent review 36 cases of small bowel cancer (4) and 20 cases of colon cancer (5) were reported. Weedon et al. (9) calculated the risk of developing carcinoma to be 20 times greater in Crohn's enterocolitis than in a control population. Using life-table methods the 10-year probability of remaining cancer free was 99.7 per cent, the 20-year probability 97.2 per cent. In our patient the long-lasting history of Crohn's colitis with several minor complications and the multiplicity of colonic carcinomas speak in favor of a causal relationship between the chronic inflammation and the development of malignancy.