Malaria is a reemerging infectious disease in Korea. We experienced a case of asymptomatic P. vivax malaria accompanied by thrombocytopenia, mimicking immune thrombocytopenic purpura. The patient was exposed to mosquito 12 weeks ago. She experienced a characteristic febrile episode lasting for 2 weeks and remained asymptomatic thereafter. It was 7 weeks after the characteristic febrile episode when the diagnosis was established by the parasitemia. Malaria should be considered in the differential diagnosis of thrombocytopenia in Korea, especially in patients with febrile episodes.