Idiopathic thrombocytopenic purpura (ITP) in children is usually a self-limiting disorder. It may follow a viral infection or immunization and is caused by an inappropriate response of the immune system. Many viruses, such as human immunodeficiency virus, cytomegalovirus (CMV), Epstein-Barr virus (EBV), varicella, rubeola, mumps, and parvovirus, have been implicated in childhood ITP. This study is a retrospective chart review of pediatric patients diagnosed with virus-associated ITP at the Hacettepe University, Ihsan Dogramaci Children's Hospital from 1997 to end of 2000. In viral serological studies, the EBV, CMV, and rubella antibodies were investigated for all patients at diagnosis (ELlSA). The proportion of children whose ITP was associated with documented acute viral infection was 13.3% in this group. In the present study, clinical manifestations and laboratory data of virus-associated or not associated groups are similar except age. Median age of the virus-associated group is younger than that of the other, but it is not statistically significant.