Detection of cytomegalovirus (CMV) by centrifugation culture was compared in MRC-5 and HFF cells. At 24 hr 47 of 130 specimens (36%) were positive for CMV, 45 in MRC-5, and 35 in HFF cells. At 48 hr 45 specimens were positive in both MRC-5 and HFF cells. MRC-5 cells appear to be superior for the detection of CMV at 24 hr in centrifugation culture; however, both lines are comparable at 48 hr.