We report 8 patients with end stage renal disease on maintenance hemodialysis who had pyocystis, pyonephrosis or a perinephric abscess. Delay in diagnosis was frequent because the urine-deprived bladder and kidneys were dismissed as potential sites of infection. Treatment of pyocystis with bladder irrigations often was successful and obviated cystectomy. Pyonephrosis or perinephric abscess was a more serious problem and required unilateral nephrectomy.