123 patients who had been treated for carcinoma of the bladder and who were clinically recurrence-free at the time of their initial Makari skin test are being followed-up; 77 were negative and 46 positive. 48 of these patients have been followed-up so far, for 3-9 months, with cystoscopic review and repeat Makari testing; 75 have still to be followed-up. The high initial positive rate of 37% has been largely explained by the discovery of a recurrent tumour at the first cystoscopy after the test. The concordance between tumour status and repeat Makari testing indicates its ability to detect early recurrence.