Detection of cytomegalovirus has been carried out in 178 clinical samples in order to compare the effectiveness of two distinct commercial immunofluorescence reagents: anti-CMV early nuclear protein (Du Pont) and CMV culture identification (Syva Micro-Trak). In 61 of the samples we observed positive reaction to either of the two procedures (Shell-vial and, or, cellular conventional culture). Sensitivity was 0.92 for Du Pont reagent, 0.79 for Syva reagent, and 0.93 for the conventional cellular culture. In the overall samples we observed a higher incidence of fluorescent focus using Du Pont reagent that using that of Syva.