Because no complete long-term follow-up of visual status after pituitary ablation has been reported, records were reviewed on all 40 patients undergoing sectioning of the pituitary stalk for diabetic retinopathy at the Mayo Clinic from 1961 through 1968. One patient died and another was blind immediately postoperatively. One patient was lost to follow-up after 125 months. Twenty-seven patients have died after a follow-up interval of 7 to 120 months (mean, 63 months). The last available evaluation of these patients indicated stable or improved visual acuity in 20 patients. Eleven patients remain alive. Seven of these have stable or improved visual acuity and retinopathy. We conclude that although late post-operative mortality is high, in carefully selected patients with florid retinopathy but no fibrosis, pituitary ablation is an effective method for maintaining visual acuity.