OBJECTIVES: To describe the incidence, pattern, and outcome of priapism in homozygous sickle cell (SS) disease. METHODS: Regular review, for periods up to 40 years, was done of all 162 males with SS disease detected during the screening of 100 000 consecutive non-operative deliveries at the main government maternity hospital in Kingston, Jamaica, between June 1973 and December 1981. RESULTS: Priapism occurred in 52 (32.7%) patients overall, the incidence rising steeply in late adolescence to 32% by age 20 years and a cumulative incidence of nearly 60% of patients by age 40 years. Many cases were elicited only on direct questioning because of embarrassment and the lack of realization that priapism complicates SS disease. Initial events were recurrent stuttering episodes in 39 patients, a single short-term event in six patients and a major attack (more than six hours) in seven patients. Erectile function was preserved in almost all patients with simple stuttering or single events. Major attacks (> 6 hours) occurred in 17 patients, preceded by stuttering episodes in nine, by a single event in one, and occurring de novo in seven. In these, erectile function was unknown in five, deemed satisfactory in five (sometimes improving over three years), weak in three and impotence persisted in four (two with major attacks three and six months previously). CONCLUSION: A history of stuttering priapism should be routinely enquired and prophylactic measures used if attacks exceed once weekly. Major events generally result in short-term impotence, but the late recovery of erectile function cautions against the early insertion of penile prostheses.