A characteristic pattern in the occupational distribution of idiopathic inflammatory bowel disease (IBD) could help to focus research with regard to its etiology or reveal the nature of possible environmental risk factors. The present study analyses occupational mortality from Crohn's disease and ulcerative colitis in England and Wales during 8 consecutive years. Mortality of various occupations was expressed as proportional mortality ratio (PMR) or standardized mortality ratio (SMR). From 1979 to 1986, 321 men aged 16-74 years died from Crohn's disease, and 406 men died from ulcerative colitis. The respective number in women were 561 and 429. In men, there was a correlation between PMR and SMR among various occupations, with r = 0.80 and 0.65 for Crohn's disease and ulcerative colitis, respectively. A relatively low occurrence of male IBD was found in occupations associated with physical work, lower social status, and farming. By contrast, high mortality from IBD tended to be associated with physically less demanding work, sedentary occupations, and type of work which is done indoors.