During the period November 1989 to March 1991 a total of 330 patients (269 males and 61 females) with signs and symptoms of uncomplicated lower genital tract infections with Neisseria gonorrhoeae were treated at a sexually transmitted disease clinic in Kampala, Uganda. Patients were randomized for treatment with either intramuscular ampicillin/sulbactam (1 g ampicillin/0.5 g sulbactam), plus 1 g probenecid orally, or ceftriaxone (250 mg). In those cases where N. gonorrhoeae was isolated and the patients returned for a follow-up visit, 70/74 (95%) of the patients treated with ampicillin/sulbactam and 71/72 (99%) of those treated with ceftriaxone had favourable clinical outcomes. All 24 patients with penicillinase-producing N. gonorrhoeae (PPNG) treated with ampicillin/sulbactam had a favourable clinical outcome compared with 95% (20/21) of those with PPNG treated with ceftriaxone. The infecting pathogen was eradicated in 65/71 (92%) of the evaluable patients treated with ampicillin/sulbactam and in 60/63 (95%) of the ceftriaxone group. Both drug regimens were well tolerated and there were no reports of adverse drug effects. In summary, in a predominantly male group of clinic patients in Kampala, Uganda, ampicillin/sulbactam was as safe and effective as ceftriaxone in treating uncomplicated gonococcal infections of the lower genital tract caused by either PPNG or non-PPNG strains.