U-373MG astrocytoma cells are susceptible to human cytomegalovirus (CMV) infection and offer the advantage of a continuous cell line for clinical laboratory use. U-373MG to MRC-5 cells for detection of CMV by centrifugation culture were therefore compared. At 20 h, 10 (6.1%) versus 12 (7.4%) of 163 clinical specimens were positive for CMV, and at 40 h, 12 (7.4%) versus 17 (10.4%) were positive in U-373MG and MRC-5 cells, respectively. Substantial toxicity was found in U-373MG cells (84%) when inoculated with blood specimens. For detection of CMV in centrifugation culture, MRC-5 cells are superior due both to higher sensitivity and lesser toxicity.