The clinical applications of azithromycin in gonorrhoea, often complicated by simultaneously acquired infection with Chlamydia trachomatis, are reviewed in this paper. Clinical trials from major centres in Europe are compared with a large, more recent US study. At the present time, azithromycin is recommended throughout the world as a useful antibiotic in the treatment of gonorrhoea. It has several advantages in that it can be given as single-dose therapy, it can be given where the causative pathogen of urethritis/cervicitis is uncertain, and it is often, therefore, most useful in acute therapy where there is no immediate microbiological back-up. All these considerations are reviewed in detail.