To study the clinical usefulness of the determination of urinary polyamine levels, voluntary urine of several urological diseases including 56 bladder tumor patients was analyzed by high performance liquid chromatography. The obtained values were adjusted by the concentration of urinary creatinine and expressed as the unit of mumol/g creatinine (mumol/g Cr) From the measurement of 8 normal adults, the normal upper limit of each polyamine was decided by mean + 2SD, and the limit for total polyamine was 59.1 mumol/g Cr, putrescine 38.1 mumol/g Cr, spermidine 16.6 mumol/g Cr and spermine 9.2 mumol/g Cr, respectively. In the patients with non-neoplastic benign urological disease, the polyamine levels were statistically not different from those of the normal adults. In the case of bladder tumor, the urinary levels of total polyamine, putrescine and spermine were significantly elevated compared with the control group. The true positive rate of this determination in bladder tumor patients was 26/56 (46%) by total polyamine level, 21/56 (38%), by putrescine level, 11/56 (56%) by spermidine level and 16/56 (29%) by spermine level. Grade or stage of the bladder tumor did not have any significant correlation with the urinary polyamine level. This determination would not be included in routine clinical examinations due to the difficulty of measurement, difference of urine sampling and lack of high sensitivity and specificity.