Summary: The examination of 100 medical patients, including liver biopsy, revealed Steatosis hepatis in 38 cases, no steatosis in 62 cases. Of the 38, 27 were chronic alcoholists, the remaining 11 having various serious affections. On the basis of our experience with liver biopsy on the whole, we always regard fatty infiltration in the liver as a pathological find. Severe Steatosis hepatis is of frequent occurrence in chronic alcoholists (27 of 31 alcoholists had steatosis). Only a small percentage of these also had cirrhotic changes. Steatosis hepatis is not a stable condition, but may disappear in the course of weeks or months. Treatment with B1 vitamin may possibly have something to do with this disappearance. Pronounced steatosis was found in one case of Icterus intermittens juvenilis, in which there was no alcoholism.