Heavy water or deuterium oxide is a promising component in different areas of medicine. A preliminary study was carried out to assess the effect of D2O on growth of Salmonella typhimurium and Salmonella enteritidis for its future application as thermostabilizer or stabilizing molecule for development or storage of veterinary biologicals for prophylactic and therapeutic purposes. In the study, the growth curves of S. typhimurium and S. enteritidis were studied spectrophotometrically in H2O and 50, 70 and 90% D2O media for a period of 12 hours by recording the optical density (O.D.) readings at an hourly interval. In freshly inoculated H2O medium, both the organisms adjusted very fast with no remarkable lag medium and the maximum log period observed was of 6 to 8 hours. In case of S. typhimurium, generation time observed was 27.90 min. and growth rate constant was 2.15, whereas in case of S. enteritidis, the generation time was 28.23 min. and growth rate constant was 2.12. Incorporation of D2O in 50% concentration did not show effect on growth rate of S. typhimurium and S. enteritidis, however, the growth rate of S. typhimurium in 50% D2O medium was observed slightly greater than in H2O medium. Whereas, the increased generation time observed in higher concentrations of D2O and the net yield of growth was inversely proportional to the percentage of D2O incorporated.