Clinical effect of cefadroxil (CDX) against urinary tract infections was reported herein. CDX, a daily dose of 0.75 g t.i.d., has been applied for the treatment of (I) 40 cases with simple UTI for average 6.4 days and (II) 47 cases with the complicated UTI for average 8.9 days. Rates of effectiveness were obtained 95% in (I) and 57% in (II). Side effects were noted in 10 cases (9.3%) out of total 107 cases.