The present study aims at an assessment of hepato-splenomegaly in infectious mononucleosis (IM). In 29 patients admitted to the ENT department with IM, based on the typical clinical and laboratory findings, including a positive mononucleosis test in most cases, the size of the liver and spleen was estimated by ultrasonic scanning on days 1, 3, 5, 10, 20, 30, 90 and 120 after admission.