Abstract:Computers are widely used in recent years but their effects on human health completely are known. The aim of this study was to investigate possible effects of computer use on human salivary oxidant / antioxidant system. Ten subjects were included in the study. Three saliva samples were taken from the subjects. First was obtained before computer use, second and third samples were obtained two and four hours after they started computer use. Malondialdehyde (MDA) levels and superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and adenosine deaminase (ADA) enzyme activities were measured in each saliva sample. Malondialdehyde (MDA) level (mean ± standard deviation) was found to increase in the saliva samples obtained after computer use. SOD and ADA activities decreased but, CAT activity increased during this period. Our results show that computer-released radiation causes changes in enzymatic antioxidant defense system and, leads to oxidant stress in saliva samples from subjects. It has been suggested that subjects who use computer intensively should be consumed more antioxidant foods in order to prevent probable oxidation reactions in their bodies.