Twenty-eight trials conducted on women with uncomplicated cystitis were reviewed comparing various treatment times or various antibiotics administered as single-dose or 3-day courses. With all antibiotics, a single-dose was less efficient than a 3-day or greater than or equal to 5-day treatment in eradicating bacteriuria. The difference was more pronounced with beta-lactams than with trimethoprim/sulfonamide combinations. With the latter antibacterial agent, no benefits were achieved by increasing treatment times to greater than or equal to 5 days. Beta-lactam antibiotics were more effective when administered for greater than or equal to 5 days than when given as a 3-day course. Short-term treatment was more effective with trimethoprim/sulfonamide than with beta-lactams. Adverse reactions did not increase with treatment time when penicillins or norfloxacin was used, which was the case with oral cephalosporins. With trimethoprim/sulfonamide combinations, adverse reactions increased markedly when treatment was given for greater than 3 days. In conclusion, single-dose treatment is less efficient than treatment for greater than or equal to 3 days, beta-lactams should be administered for greater than or equal to 5 days, the optimal treatment time with trimethoprim/sulfonamide combinations seems to be 3 days, and considerable differences exist among various antibiotics.