A BSTRACT Aim: This study aimed to assess the dental caries experience among dental students with different levels of dental environment stress in relation to salivary nitric oxide (NO) and flow rate of whole unstimulated saliva. Materials and Methods: The study involved 300 dental students. They were classified into three categories (mild stress, moderate stress, and severe stress) according to dental environment stress questionnaire (DESQ); clinical examination for dental caries was carried out. Unstimulated salivary samples were collected from the mild and severe stress groups for measuring the salivary flow rate. Estimation of salivary NO was carried out by using salivary NO test strips. All data were analyzed using the Statistical Package for the Social Sciences software, version 21.0 (SPSS, Chicago, Illinois). Results: Dental caries experience was higher among severe and moderate stress groups with nonsignificant differences ( P > 0.05). Mean value of salivary flow rate was lower among severe stress group with nonsignificant differences ( P > 0.05). NO was significantly higher among severe stress group ( P < 0.05). Flow rate was weak negatively correlated with caries experience among both mild and severe stress groups except for the decay surface (DS), which was weak positive among mild stress group. NO was weak negatively correlated with DS among both mild and severe stress groups. All these correlations were statistically not significant ( P > 0.05). Conclusion: Dental environment stress appears to affect oral health, shown by higher dental caries among dental students with severe dental environment stress by affecting the normal level of salivary flow rate and NO.