353 adult patients aged from 26 to 90 years with complicated urinary tract infections were investigated in a double-blind randomised multicentre trial in which 176 patients received cefetamet pivoxil (CAT) 500mg twice daily and 177 patients cefuroxime axetil (CMX) 250mg twice daily for 7 days. The groups were comparable. The bacteriological findings that were evaluated 7 to 10 days post-therapy were the main criteria for assessment of efficacy. Patients were followed up for 5 ± 1 weeks post-therapy. Bacteriological assessment was possible in 310 patients, i.e. 156 patients from the CAT group and 154 from the CMX group. Escherichia coli proved to be the predominant causative pathogen in this patient series, occurring in 68.4%. The overall bacteriological outcome was successful in 97.4% of the patients receiving CAT and 90.3% to whom CMX was given. The pathogens persisting in the CAT group were E. coli (1), Proteus rettgeri (1), and Klebsiella pneumoniae (1), while in the CMX group the pathogens were E. coli (4), Proteus spp. (2), K. pneumoniae (1), Enterobacter sp. (1), Serratia sp. (1), Levinia sp. (1) and mixed infection (1). The overall clinical outcome was successful in 137 (87.8%) of 156 assessable patients treated with CAT and in 129 (83.8%) of 154 patients to whom CMX was administered. The incidence of adverse events was 11.9% in both treatment groups. All adverse events were mild to moderate in severity and predominantly gastrointestinal. Treatment was withdrawn prematurely in 1 patient receiving CMX because of rash. Based on the presented data, we conclude that cefetamet pivoxil in the recommended dosage of 500mg twice daily is effective and well tolerated in the treatment of patients with complicated urinary tract infections.