Seventy-five patients presented with the complaint of pruritus ani. The following prospective studies were employed to evaluate groups of these patients; (1) laboratory, including blood count, stool examination for ova and parasites, urinalysis, Sequential Multiple Analysis-12 serum studies, stool pH, and skin scrapings for fungi; (2) Minnesota Multiphasic Personality Inventory; (3) anal manometry; (4) elimination of dietary factors, and (5) topical ointment application. Many patients were concerned that a cancer caused the symptom. Once reassured, they tolerated the pruritus. Forty-eight to 50 per cent of these patients had poorly formed stools or incomplete stool evacuation; thus, soiling was frequent. An underlying skin problem was found in six patients with psoriasis and in one with erythrasma. Patients tended to worsen the problem by application of many medications and overzealous cleaning. Minor surgical problems of the anus should be corrected before other managements are instituted. Idiopathic pruritus ani responds to anal cleanliness, dietary discretion with avoidance of specific items by some patients, bowel habit regulation, and a mild topical hydrocortisone cream.