A simple, sensitive, and specific method for measuring the concentration of platinum in urine is reported. Urine specimens for this study were collected from laboratory staff and from patients who received treatment with cisplatin as a chemotherapeutic agent for cancer. The concentration of platinum was determined by inductively coupled plasma atomic emission spectrometry. The entrance slit of the simultaneous spectrometer, normally used for correction of optical alignment, was moved by the micrometer to shift the emission line of platinum onto the detector originally assigned to tellurium. Background correction was applied to compensate for spectral interference and thus enhance accuracy. The analytical detection limit was 0.05 mg Pt/L. At 10.0 mg Pt/L in spiked urines the recovery was 93.3% with a relative standard deviation of 6.6%. Storage for 10 days at 4 degrees C did not affect the recovery.