A total of 174 patients (347 eyes) with retinitis pigmentosa were categorized by genetic type and assessed as to the degree of central visual loss. The degree of central visual loss was mildest in cases of autosomal-dominant inheritance and most extensive in cases of X-linked recessive inheritance. Slightly more than one third (34%) of all eyes had acuity of 20/200 or less, while only 55% had vision of 20/60 or better. The data in this study provide general guidelines for counseling individual patients with retinitis pigmentosa as to the potential and extent of future central visual loss.