BACKGROUND Deaths of living liver donors have been reported in western countries, whereas the morbidity and mortality of such donors in Japan, one of the leading countries for living liver transplantation, have not been reported in detail. We aimed to review the operative morbidity and mortality of such donors in Japan. METHODS 1853 donors of 1852 living liver transplants done in 46 liver transplant centres, and registered in the database of the Japanese Liver Transplantation Society, were assessed for eight donor-related factors of morbidity and mortality. Data for 1841 donors were analysed. RESULTS No perioperative mortality was recorded since inception of the liver transplantation programme in Japan from Nov 13, 1989, to April 11, 2002. 244 postoperative complications were reported in 228 (12%) donors. The frequency of complications was significantly higher in donors of the right liver lobe than in those involving the lateral segment, and left lobe graft (p<0.0001, and p<0.0001, respectively). Postoperative hospital stay was significantly longer in donors of the right lobe (mean 19.7 [SD 13.0]) than in those of the lateral segment (14.2 [7.6]), left lobe (14.0 [6.5]), and left lobe and caudate lobe (16.3 [12.1]). Re-operation related to donor hepatectomy was done in 23 donors. CONCLUSIONS By contrast with western countries, no perioperative mortality was recorded in living liver donors in Japan. However, a proportion of these donors developed serious complications. This morbidity should be reduced to maintain zero mortality in living liver donors.