TPS levels were determined in the serum and urine of 136 Egyptian patients with infiltrating bladder cancer and compared with the levels in 45 normal controls and 45 patients with urinary tract Bilharziasis. At 95% specificity the sensitivy in bladder cancer patients in serum and urine was 34.6% and 96.3%, respectively. Elevated TPS levels did not correlate with histological type, staging, grade, lymph node involvement or Bilharziasis. The determination of urinary TPS could probably be a useful tool in the follow-up of patients with superficial transitional cell carcinoma of the bladder. This urine test is less invasive and cheaper than cystoscopy and could, eventually, in combination with cytological examination of the urine, indicate the need of less frequent cystoscopy.