An FITC-conjugated monoclonal antibody reagent containing three CMV-specific monoclonal antibodies was evaluated for the rapid detection of CMV in bronchoalveolar lavage (BAL) cytospin preparations by direct IF (DFA). Eighty-six BAL samples from 72 marrow transplant patients were inoculated into both centrifugation and standard cell culture. CMV was detected in 49/86 (57%) BAL samples. DFA detected 37/46 (80%) samples which were positive in centrifugation culture. While DFA staining lacked the sensitivity (overall sensitivity 38/49, 78%) to replace either standard or centrifugation culture, the total laboratory time needed to complete the DFA was only 1.5 h and its concurrent use with centrifugation culture can provide rapid specific diagnosis of CMV pneumonia.