Priapism is regarded as an uncommon disease in white populations, although no previous research has been done into its incidence in a certain geographical area. All cases of priapism in Finland during the years 1975-90 are reviewed here. Its incidence varied from 0.34 to 0.52/100,000 males per year, being very stable during the whole period of 16 years, when cases due to intracorporeal injections for treatment of impotence are excluded. Typical patients were 40-50 years old, and the incidence was higher in the eastern part of the country. Most cases of priapism were seen during the lighter half of the year, between March and August (65%). The use of intracorporeally injected vasoactive drugs for impotence increased the incidence more than two-fold.