Peyronie's disease is an idiopathic disorder in which an inflammatory fibrosis occurs in the tunica albuginea of the corpora cavernosa which causes the erect penis to become deformed. Peyronie's disease has a prevalence of 1% in men over age 50 years. Paget's disease of bone is a chronic skeletal disease with areas of increased bone turnover leading to pain, deformity, and in some cases arthritis. Because of a high rate of Peyronie's disease in subjects in a Paget's disease industry-sponsored drug trial, we asked whether there was an association between Peyronie's disease and Paget's disease of bone. We evaluated 61 men with Paget's disease attending our clinic for metabolic bone disease in a tertiary referral hospital, reviewed hospital records of all men discharged from our three hospitals with the diagnosis of Peyronie's disease, and mailed a validated questionnaire about shape of the erect penis to 1500 male members of the Paget Foundation. In the clinic population of men with Paget's disease of bone, 51 of 61 (83.6%) reported having normal erections; 10 patients (16.4%) were impotent. Sixteen of the 51 men (31.4%) had developed a bend or deformity in their erect penis which was confirmed by a urologist's examination to be Peyronie's disease. When the men with Paget's disease with and without Peyronie's disease were compared, there was no difference in their ages, years with Paget's disease, or serum alkaline phosphatase level. Upon medical record review, 1 patient of 262 (0.4%) with Peyronie's disease was found to have Paget's disease of bone. The men with Paget's disease returned their questionnaires for a response rate of 44.8% and reported Peyronie's disease with a prevalence of 14.5%. We suggest that Peyronie's disease is associated with Paget's disease of bone. Furthermore, we suggest that Peyronie's disease may be a previously unrecognized complication of Paget's disease of bone.