The aim of this study was to evaluate the cytotoxic effects of Cigarette Smoke on the human peripheral blood lymphocytes in the presence of stimulated or non-stimulated saliva in an in vitro model.Ten healthy volunteers in the age range of 21 to 29 were selected and samples of peripheral blood lymphocytes and saliva (whole and stimulated saliva) collected . Peripheral blood lymphocytes suspensions (PBS) were taken and exposed to 6 different media. Samples were collected from all media at both 20 and 80 minute time points. The survival rates of PBL were then determined at both 20 and 80 minute time points.The cell survival rates following exposure to cigarette smoke (CS) in the presence of PBS supplemented with whole or stimulated saliva were significantly lower at 80 minutes when compared with the 20 minute rates (P<0.05).Tobacco effects were significantly increased in the presence of saliva especially stimulated saliva.