Birth weight is a powerful predictor of infant growth and survival. Evidence now shows that children born with low birth weight face an increased risk of chronic diseases and have many health problems including oral health. The aims of this study were to assess the salivary flow rate, viscosity, and salivary cortisol among low birth weight kindergarten children aged 5 years old in Hilla centre, in relation to dental caries and compares them with the normal birth weight children of the same age and gender. Materials and methods: The total sample involved 80 children (40 low birth weights and 40 normal birth weights) aged 5 years old. The diagnosis and recording of severity of dental caries was recorded through the application of d1-4mfs index according to the criteria described by Muhlemann (1976). The stimulated saliva was collected from the total sample under standardized conditions and then analyzed for measuring salivary flow rate and viscosity, in addition to estimation of salivary cortisol by special cortizol kit using VIDAS® Cortisol S. Results: The mean rank of dmfs, ds, ms and fs were found to be higher among low birth weight than normal birth weight groups, with a statistically significant difference for dmfs, ds (P 0.05). Concerning the ds grade, data analysis showed a significant difference only for d 1 grade (P 0.05). The viscosity of saliva was found to be highly significantly higher among low birth weight than normal birth weight groups (P 0.05). Conclusion: The results of the current research revealed that low birth weight status affect oral health conditions.