The efficacy of metronidazole and tinidazole has been compared in 31 patients with hepatic amoebiasis. Only those with unequivocal clinical, radiological and laboratory evidence of hepatic amoebiasis were included; diagnostic and therapeutic aspiration was performed where necessary. 15 patients received metronidazole and 16 tinidazole, in random order. The 2 groups were comparable. Both drugs were given orally in a single daily dose of 2g for a minimum of 3 days, with treatment extended if considered clinically advisable. 12 of 15 patients (80%) were cured with metronidazole given for an average period of 7 days (range 4 to 14 days). 15 of 16 patients (93.8%) given tinidazole were cured and the mean duration of treatment was 4 days (range 3 to 6 days). There were fewer side-effects with tinidazole. In this study of hepatic amoebiasis in Bangladesh, tinidazole was found to be superior to metronidazole in overall efficacy because a shorter course of treatment was necessary and it caused fewer side-effects.