A 20-year follow-up evaluation of young men with fixed and reproducible orthostatic proteinuria showed no evidence of progressive renal disease. Follow-up information was obtained on 43 of the original 64 patients and detailed information was secured on 36. All had normal renal function and only six patients continued to show qualitative proteinuria. The prevalence of hypertension found was similar to that of a comparably aged group of the general population. The 20-year prognosis of patients with fixed and reproducible orthostatic proteinuria is excellent.