The authors assessed the relationship between early objective response to panretinal photocoagulation (PRP) and the subsequent long-term visual outcome in 59 eyes of 59 consecutive patients who developed proliferative diabetic retinopathy while under the care of a retinal specialist. Thirty five eyes (59%) had regression of high-risk retinopathy characteristics within 3 months of treatment. Eighteen of these eyes (52%) had a final visual acuity of 20/20 or better with a mean follow-up of more than 4 years. Only 2 of the 24 nonresponder eyes (8%) had visual acuity of 20/20 or better. Thirteen of the responder eyes (37%) sustained a delayed vitreous hemorrhage, which was usually self-limited. Three responders underwent vitrectomy with excellent visual results. The authors conclude that the beneficial effect of PRP on visual outcome is directly related to the regression of retinopathy risk factors and that the long-term visual prognosis in high-risk eyes manifesting a favorable initial response to PRP is excellent.