Clinical efficacy of maxaquin versus ciprofloxacin against complicated or/and recurrent urinary infections (62 patients primarily with chronic pyelonephritis with nephrolithiasis) proved higher (92.3% vs 80.0%) in equal microbiological activity (73.2% vs. 73.4%) of the drugs. Maxaquin was less active in enhancing the culture resistance. Both quinolones had no negative effects on the studied systems of the body's antiinfectious resistance and promoted partial correction of dysbiotic manifestations on the colon mucosa. Side effects of both drugs occurred with similar frequency and severity, starting earlier in administration of maxaquin. The authors offer to manage urinary infections in adults effectively with maxaquin in a dose 400 mg once a day and ciprofloxacin in a dose 500 mg twice a day by 7-14-day courses.