The reliability of using visible haematuria as an indirect screening technique to detect Schistosoma haematobium was investigated in 418 school children from Dar es Salaam, Tanzania. The sensitivity of the test varied significantly with the time of urine collection and the portion of the micturition stream examined. Whereas sensitivity was 50% and accuracy 73% in the morning, in the afternoon sensitivity and accuracy had increased to 75% and 97% respectively if terminal urine samples were examined. It is concluded that visible haematuria is a sensitive, highly accurate and reliable indirect screening test for urinary schistosomiasis provided that the method of collection and examination of the urine samples is standardized.