At the end of World War II, the Allied Powers tried numerous Japanese defendants in locally based war crime trials across Asia. This article examines a particular set of British trials conducted in Singapore against Japanese defendants accused of POW abuse onboard Japanese 'hell-ships'. These cases address issues of omission and attribution, which continue to be relevant and much debated. First, the defendants were held reponsible for failures to act rather than for any positive acts of cruelty. Second, these cases considered different arguments linking the mid-ranking defendants to the crimes of POW ill-treatment. This article will analyse the 'hell-ship' cases against the prism of contemporary jurisprudence with the aim of identifying possible lessons as we continue to deal with issues of omissions and attribution in international criminal law today.