Non-communicable diseases, arising out of changing lifestyle habits of people, are the foremost causes of mortality and morbidity worldwide. Most of these diseases occur in low and middle-income countries. Chronic diseases can be managed with the help of health behaviors such as proper diet, physical exercise, adherence to medication, and avoidance of health risk behaviors such as smoking, alcohol consumption, sedentary lifestyle, etc. The social cognitive theory addresses the role of personal and environmental factors in an individual's health behavior. The current study aims to understand the role of social cognitive theory on physical activity and dietary behavior amongst individuals diagnosed with type-2 diabetes. MethodsA correlational study was conducted among 225 participants with type-2 diabetes, who are under medication. The data was collected using social cognitive questionnaire for physical activity & dietary behavior and Health-Promoting Lifestyle Profile II. Descriptive statistics, Pearson's correlation coefficient and multiple linear regression analysis were used to analyze the data. ResultsIt was found from the study results that, all the domains of social cognitive theory were significantly correlated with physical activity (p<0.001) and the SCT domainsself-regulation (p<0.001), social support (p<0.001), and outcome expectancy (p<0.05) were significantly correlated with dietary behavior. The results of multiple linear regressions indicated that the domains self-regulation and self-efficacy were the significant predictor for physical activity behavior (R 2 =.21, p ≤ 0.001) while the domains social support and self-regulation were the significant predictor of dietary behavior (R 2 =.09, p ≤ 0.001). ConclusionThe study results show that there is an influence of social cognitive domains on physical activity and dietary behaviour. Further, this study suggests that social cognitive theory based intervention can be used to promote healthy behaviour.