Until 1962 all patients with acute viral hepatitis admitted to the Medical University Clinic at Marburg were treated with laevulose infusions. This treatment was discontinued in 1963. Follow-up examination of 109 patients with acute hepatitis who had been given laevulose infusions and 91 who had not (both groups being similar as to age and sex and average severity of the disease) revealed that there was no significant difference between the two groups with regard to the fall in transaminase levels during the first seven weeks after the onset of jaundice. Serum-bilirubin concentration was also similar. On the other hand, the abrupt fall in serum-bilirubin concentration in the second to third week of illness, so typical of the spontaneous course, occurred a week later in those who had been given laevulose infusions. Duration of the disease until normalization of transaminase and serum-bilirubin concentration was not favourably influenced by laevulose infusions. It is concluded that such infusions do not have a favourable effect on the course of acute viral hepatitis.