Six autopsies were worked up from the phosgene catastrophe in Hamburg. Deviation from the previously communicated reports depended upon the fact that this time phosgene was at work, and not the so-called war gases. As to the main seat of morphological changes, the upper air passages were peculiarly exempt. There were injuries of the small bronchioles, the lung parenchyma, and the vessel walls, resulting in a marked impairment of the lesser circulation, with most of the significant changes in the other organs easily accountable. Contrary to the pharmacological literature, only part of the latter could be explained by immediate poisoning. Here belong degenerative changes in the liver, heart, and, especially, so far unobserved brain changes that could not be explained by simple circulatory disturbances. In a fatal case where death occurred 11 1/2 days after the poisoning, thrombi in both ventricles with emboli in the left coronary artery were the immediate causes of death. There were interesting organizations in the lungs, also regenerative changes with corpora amylacea.