A randomized, comparative study undertaken in Nairobi, Kenya and a non-comparative evaluation undertaken in Carletonville, South Africa have both shown that a single oral dose of azithromycin 1 g is effective in the treatment of the genital ulcer disease (GUD), chancroid, with cure rates of 89% and 92% recorded respectively. While treatment failure was associated with human immunodeficiency virus seropositivity and lack of circumcision in Kenya, no such association could be found in the South African study. In both series, azithromycin treatment resulted in cure of both Haemophilus ducreyi culture-positive and culture-negative cases of GUD, including two cases subsequently diagnosed as lymphogranuloma venereum. A combination of single-dose azithromycin with single-dose benzathine penicillin may provide effective 'single-visit' syndromic treatment for GUD in many developing countries.