Severe thrombocytopenia secondary to cytomegalovirus (CMV) infection is rare in immunocompetent hosts. We describe a case of severe thrombocytopenia secondary to CMV infection in an immunocompetent 30-year-old man who presented with pyrexia and bleeding tendency. A diagnosis of immune thrombocytopenia (ITP) was made following hematological and serological testing, and bone marrow aspiration. Acute CMV infection was confirmed by serological testing, antigenemia, and detection of CMV-DNA. Corticosteroid therapy was ineffective and intravenous immunoglobulin (IVIG) was therefore administered. This resulted in immediate recovery of the platelet count and cessation of nasal bleeding. Early IVIG administration should be considered in steroid-resistant cases.