We studied 220 patients (138 men and 82 women) with uncomplicated gonorrhoea who were entered into a randomised double blind trial and treated with either Augmentin (amoxycillin 3 g and potassium clavulanate 125 mg) or amoxycillin 3 g, with probenecid 1 g by mouth in all cases. Seven (6.5%) of 108 patients treated with Augmentin were still culture positive after treatment, compared with 15 (13.4%) of 112 of those treated with amoxycillin. Penicillinase (beta lactamase) producing strains of Neisseria gonorrhoeae (PPNG) were found in 23 (10.5%) patients, of whom 10 were treated with Augmentin and 13 with amoxycillin. Treatment failed in all 13 patients who received amoxycillin. Augmentin was shown to be an effective treatment for gonorrhoea caused by PPNG strains.