Thirty patients with pyogenic liver abscess were admitted to King's College Hospital between 1967 and 1978. The overall mortality was 43 per cent (13 patients). The diagnosis was often difficult and in 10 patients the correct diagnosis was not made until post-mortem. Of the 20 patients diagnosed and treated, 17 had a unilocular abscess, of whom 16 survived. The remaining 3 had a multicentric abscess, and only 1 of them survived. Difficulty in diagnosis was sometimes increased by misleading results fom special investigations. Clinical awareness leading to early diagnosis, drainage and broad spectrum antibiotic treatment remain the prerequisites for cure.