Background There has been increasing interest in the research into cytomegalovirus (CMV) pneumonia after liver transplantation (LT). This study was undertaken to investigate the immunomodulatory therapy of CMV pneumonia after LT.Methods Six patients with CMV pneumonia after LT from October 2003 to November 2005 were analyzed retrospectively. They were diagnosed according to clinical manifestations, chest X-ray findings and pathogenic changes and given comprehensive therapy including mainly immunomodulation therapy and anti-viral medication. At the early stage of CMV pneumonia, the dose of immunosuppressive agents was decreased or ceased, instead replaced by immunoenhancement therapy. During recovery period from CMV pneumonia, the dose of immunosuppressive agents was given again or enhanced, and immunoenhancement therapy was ceased.The liver function of the patients was monitored closely during the treatment.Results In this series, five patients were survived and one died. The liver function of the six patients remained normal during the treatment, and no episode of acute rejection took place.Conclusions Poor immunity is the pathogenic basis of CMV pneumonia after LT. At early stage of CMV pneumonia, the immunity of the patients should be enhanced, and during the recovery period from CMV pneumonia, immunosuppresants shoud be given again but immunoenhancement therapy ceased. Individualized immunomodulatory therapy is essential to the treatment of CMV pneumonia after LT.