Since the treatment of chancroid was reviewed in 1982, the results of subsequent treatment trials have offered the clinician additional therapeutic choices as well as shorter courses of therapy. Erythromycin (500 mg four times a day for seven days) provides consistently effective treatment for cases acquired throughout the world, although erythromycin-resistant strains have been isolated in Singapore. Sulfamethoxazole and trimethoprim (800 mg/160 mg orally twice a day for seven days), ceftriaxone (250 mg intramuscularly one time), and amoxicillin/clavulanic acid (500 mg/125 mg orally three times a day for seven days) are also efficacious. There is, however, significant geographic variability in the susceptibility of Haemophilus ducreyi to sulfamethoxazole and trimethoprim, suggesting this combination may become increasingly less effective, and a lack of in-depth experience in the treatment of chancroid with ceftriaxone and amoxicillin/clavulanic acid.