During the summer of 2000, a countrywide epidemic of West Nile fever (WNF) occurred in Israel, with 417 confirmed cases and 35 deaths. Immunosuppressed patients had a 31% case-fatality rate, which was significantly higher compared to non-immunosuppressed patients (13%). We describe a 42-year-old male lung-transplant recipient with serologically confirmed West Nile virus (WNV) encephalitis and deteriorating level of consciousness. He was treated with 0.4 g/kg intravenous immunoglobulin preparation from Israeli donors that contained a high titer of anti-WNV antibodies (1 : 1600). The patient showed rapid improvement within 24 h and complete disappearance of signs and symptoms within 48 h. This is the second case of an immunosuppressed patient responding to the same preparation of intravenous immunoglobulins. Larger studies are required in order to establish the therapeutic role of immunoglobulins in patients with WNF.