To demonstrate a possible association between stress factors and the presence of human cytomegalovirus (HCMV) DNA in leukocytes and in cell-free body fluids, at 2-week intervals over a 6-month period, specimens were taken for HCMV DNA testing from 11 healthy CMV-seropositive individuals who were also surveyed for stress-producing events occurring during the previous week. A positive polymerase chain reaction (PCR) signal was given in 104/127 (81.9%) urines, 73/127 (57.3%) throat washings and 68/127 (53.6%) leukocyte samples. An association was found between HCMV DNA in urine and a stress-producing event at work (p < 0.04). An association was also found between detection of HCMV DNA in throat washings and alcohol ingestion (P < 0.006) and between the presence of oral herpes lesions and the detection of HCMV DNA in leukocytes (p < 0.0019). The results suggest that viral reactivation is more common than previously thought and that stress may be a triggering event.