Background: Smokeless tobacco(ST) imperil periodontal health and also produces imbalance between reactive oxygen species(ROS) and antioxidants(AO) such as catalase(CAT) resulting in oxidative stress(OS). Hence, our study hypothesis is to investigate and compare salivary catalase levels in healthy, gingivitis, CP and CP with ST and to compare and correlate salivary catalase with clinical parameters. Methods: Hundred subjects were divided into 4 groups of 25 each, healthy, gingivitis, CP and CP with ST. Saliva samples of subjects were collected and analyzed for catalase using UV spectrophotometer at 240nm. Statistical analysis was performed using ANOVA and tukey’s post hoc analysis. Results: Salivary catalase levels were found to be significantly lower in chronic periodontitis with smokeless tobacco followed by chronic periodontitis, gingivitis and healthy subjects (p<0.001). Conclusion: Salivary catalase is valuable tool in periodontal disease diagnosis, prognosis, acts as preventive, therapeutic and in early planning of treatment modalities