The effectiveness of Cefoperazone in the treatment of urinary tract infection was evaluated in the Department of Urology, St. Mary s hospital from December 1. 1979 to April 30. 1980. In this studies, the cusative organisms were divided into 2 groups; 1) Single form. E. coli (8), Staphylococcus aureus(7), Proteus vulgaris (4), P. morganii(3), S. epidermis (1), Enterococcus(1), Klebsiella (2), N. gonococcus(1). 2) Mixed from: Proteus+E. coli(4), E. coli+other(1), Pseudomonas+Enterococcus(1), Klebsiella+other(1). Effectiveness on urological diseases. 1) Neurogenic bladder: Results were excellent in 3 cases, good in 4 cases and negative effect in 4 cases. 2) Non-gonococcal urethritis: In this group, the therapeutic results were favorable in 88.9% of all cases. (Excellent in 2, Fail in1) 3) Pyelonephritis: All(4 cases) were excellent. 4) Renal stone: Among the 4 cases of renal stone, only one case was responded to cefoperazone. 5) Two cases of urethral stricture, two cases of cystitis, one case of B.P.H. and one case of gonococcal urethritis were all excellent. No serious side effects were observed except slight dizziness in one case.