In a series of 629 consecutive retinal detachments, 20 (3%) eyes had preoperative subretinal fibrosis without preretinal fibrosis. The incidence varied in a linear fashion with the duration of the detachment, varying from 0.8% in cases less than one month old to 22% in cases estimated to be more than two years old. Nineteen of the 20 detachments were anatomically cured by scleral buckling.