This study was designed to follow up patient compliance by detection of antituberculous drugsx in urine during the course of treatment. It was conducted in the Outpatient Clinic of Pediatric Infectious Diseases, Sisli Etfal Hospital (Istanbul, Turkey). In total, 45 children with pulmonary tuberculosis participated. Patients were seen twice in the first month and once a month thereafter during the 6-month course of treatment. The second urine of the day was collected at each visit. Urine was tested for isoniazid (INH), rifampicin (RIF), and pyrazinamide (PZA). In the presence of these drugs or their metabolites, the addition of certain chemicals caused a color change in the urine. On day 15 of treatment, urine tested positive for INH in 82% of patients, for RIF in 67%, and for PZA in 73%. At the end of the second month, the ratio of adherence was 96,89, and 96% for each drug, respectively All patients were found to be adherent at months 5 and 6. We recommend detection of antituberculous drugs in urine to assess compliance to treatment. Once the defaulting patients were identified, adherence was improved by repeatedly providing patient education throughout the treatment. (C) 2003 Wiley-Liss, Inc.