BACKGROUND Cytomegalovirus (CMV) infection is typically asymptomatic in immunocompetent individuals but can cause severe complications, such as immune thrombocytopenic purpura (ITP). This case report describes an uncommon instance of CMV-induced ITP in a 36-year-old immunocompetent man who was refractory to steroids and intravenous immunoglobulin (IVIG) and responded to antiviral therapy. CASE REPORT A previously healthy 36-year-old White man presented with flu-like symptoms, including subjective fevers, anorexia, nausea, cough, and a 6.8-kg weight loss over 2 weeks. Initial laboratory test results revealed severe thrombocytopenia (platelet count 4×10⁹/L) alongside elevated lymphocyte counts and mild splenomegaly. Additional serology confirmed a positive CMV IgM antibody. The patient was identified as having ITP and was treated with high-dose methylprednisolone and platelet transfusion, leading to initial platelet recovery. However, he returned within a week with severe epistaxis and a critical drop in platelet count to 0×10⁹/L. Subsequent testing confirmed CMV infection, with a viral load of 8790 copies/mL viral load. After unsuccessful IVIG treatment, antiviral therapy with valganciclovir was initiated, leading to a sustained increase in platelet count and eventual symptom resolution. CONCLUSIONS CMV-induced ITP, although rare in immunocompetent individuals, should be considered in cases of refractory thrombocytopenia unresponsive to standard therapies. Prompt diagnosis and the initiation of targeted antiviral therapy are crucial for effective recovery, as they address the underlying viral etiology and can significantly improve patient outcomes. This case underscores the importance of including CMV in the differential diagnosis for persistent thrombocytopenia to ensure timely and appropriate treatment.