A total of 581 people (33% male, 67% female) attending general practitioners completed a questionnaire mainly on health beliefs and were then offered a fecal occult blood test (Hemoccult II) free of charge. Eighty-six percent accepted the general practitioners' offer and took the Hemoccult kit home. Of these, 51% complied (i.e., returned specimens for laboratory testing). The Health Belief Model was found to account for 12% of the variance in screening behavior. Perceived barriers to taking the test and perceived susceptibility to bowel cancer were the only components contributing significantly in the multiple regression analysis. Health Belief Model components that were predictive of initial acceptance of the test offer differed from components predictive of ultimate compliance. The influence upon compliance of family history of colorectal cancer, history of colonic symptoms, smoking habits, perceived attitudes of spouses, attitude to detection tests, and subjective stress related to the threat of bowel cancer were also investigated.