Most of the primary infections caused by Epstein-Barr virus in children are asymptomatic. In symptomatic patients, clinical presentation is variable. We describe 33 patients admitted to Suleimania Children's Hospital, Riyadh from 1409 too 1411H (1988 to 1990G) with acute primary infection caused by Epstein-Barr virus. The clinical presentation was mostly with upper respiratory tract infection, fever, lymphadenopathy, and hepatosplenomegaly. Three patients had arthralgia and three had neurological manifestations. Only four patients had atypical lymphocytes > 10%. Elevated serum alanine and aspartate aminotransferase levels were found in about 54.55 of the patients.