We carried out a prospective, parallel, and blind study on 113 blood samples from immunocompromised patients in order to compare two leukocyte extraction methods (6% dextran sedimentation and Polymorphprep separation) for cytomegalovirus (CMV) antigenemia assay. CMV was detected in 38 samples by antigenemia assay (34 by dextran sedimentation and 35 by Polymorphprep separation). No differences either in the number of positive specimens (P = 1) or in the mean CMV-positive cell counts (P = 0.41) were observed between the two leukocyte extraction methods. In conclusion, the two methods performed equally well for this assay.