Thermally injured mice that were given intraperitoneal injections of murine cytomegalovirus (MCMV) appeared to be clinically septic and to have increased mortality rates. To evaluate the possible role of MCMV infection in promoting bacterial translocation in burned mice, mesenteric lymph nodes were cultured from two strains of mice (BALB/c and CBA) that were given thermal injuries alone, MCMV alone, or both. BALB/c mice injected with 5 × 105plaque-forming units MCMV following a 15% to 16% total body surface area scald injury had increased incidence of positive mesenteric lymph node cultures compared with other groups. No intestinal mucosal histologies, mucosal dry weights, or wet-to-dry weight ratios in any animals were abnormal. Differences in cecal bacterial concentrations were not observed. Murine cytomegalovirus infection appears to enhance bacterial translocation in this model.