Between 1972 and 1984 73 patients with acute cytomegalovirus infection have been monitored. In 55 patients case history did not reveal any former disease. In 18 patients the cytomegalovirus infection was a sequela of cardiac surgery ("postperfusion syndrome"), transplantation or underlying malignant disease. After a prodromal stage which comprised unspecific symptoms in most cases various organ manifestations were noted in the course of disease. Typical cases presented hepatitis, myocarditis, Guillain-Barré syndrome with or without thrombocytopenia and (or) lympho-monocytosis. The organ symptoms were varying in degree and resolved completely within 4 to 12 weeks. Only one female patient died from congestive heart failure due to myocarditis after one year.