During the past few years major progress has been made in the diagnosis and therapy of CMV infection after allogeneic BMT. The aim of this survey was to investigate the use of diagnostic techniques, use of prophylaxis and the therapeutic strategies among members of the EBMT. Seventy centers from 20 countries responded to the survey. Sixty-seven centers (96%) routinely tried to diagnose CMV from the blood. Fifty-seven centers used standard or rapid isolation techniques. Thirty-seven centers used one of the newly developed techniques, antigenemia detection in leukocytes or PCR together with isolation, while 10 centers used one of these two techniques without standard isolation. Fifty-five centers regularly performed bronchoscopy and bronchoalveolar lavage on the suspicion of CMV pneumonia but only 12 centers required detection of CMV in specimens from the lavage or lungs as the indication to start therapy; 31 centers started therapy on symptoms of pneumonia combined with CMV detection from any site. Prophylaxis was used in 54 centers (84%). The most commonly used regimen was high-dose acyclovir which was used by 42 centers, while seven centers used ganciclovir. The strategy of early therapy was used by 53 centers (76%) and was most frequently based on detection of viremia or CMV antigen in the blood. CMV pneumonia was treated by a combination of ganciclovir and i.v. immunoglobulin by 64 centers, by foscarnet and immunoglobulin in 5 centers and by ganciclovir alone in 5 centers. CMV gastrointestinal disease was treated by antiviral therapy alone in 18 centers and by a combination of antiviral therapy and iv immunoglobulin in 46 centers.(ABSTRACT TRUNCATED AT 250 WORDS)