It has been suspected that various infections, including cytomegalovirus(CMV) infection, are associated with IgA nephropathy. In case of CMV infection, ganciclovir is known to be a treatment of choice for severe CMV infection in general. But ganciclovir has a lot of severe toxicity, so children with normal immunity are seldom treated by ganciclovir when CMV infection is suspected. On the other hand, intravenous immunoglobulin can also be used to treat CMV infection. We report a case of CMV-associated IgA nephrophaty, who was treated with deflazacort and Intravenous immunoglobulin therapy. An 11 years old boy suffered from gross hematuria for 3 days. He had proteinuria, thrombocytopenia(104,000/$mm^3$), antiplatelet antibody(＋), impaired renal function and low serum albumin. His CMV serology was CMV-IgM/IgG(＋/-) and urine CMV-PCR was positive. The renal histological findings revealed IgA nephropathy, WHO class II. His proteinuria persisted despite of deflazacort therapy(2.5 mg/kg/day). Later, intravenous immunoglobulin(1 g/kg) was administered twice. In two years, he showed no gross and microscopic hematuria, and his laboratory findings were also normalized.