Data from the Danish National Health Service records on activities of each of 146 general practices in the county of North Jutland, Denmark, were studied to determine whether the use of proctoscopy influenced the stage at which cancer of the rectum was recognized. Information for all patients in the county who received the diagnosis of cancer of the rectum was obtained from the Danish Cancer Registry. Proctoscopy was performed significantly more often in partnership practices (96%) than in single practices (81%). The frequency with which the test was used varied from 1 to 107 proctoscopies per general practitioner per year. In the 95 patients with cancer of the rectum, no relationship was found between the stage (Dukes') at the time of diagnosis and work-load, size and activity of practice, or use of proctoscopy.