The increased prevalence of obesity has serious health problems around the world and  so many variables increased possibility of overweight. This study aimed to investigate the role of irrational beliefs, health locus of control and health-oriented lifestyle in predicting the risk of obesity. This research had a case-control design. Population consisted of members of Iranshahr neighborhood in Tehran. Sample consisted of 100 patients and 100 healthy one which was mathch by each other. Data ware gatherd by health Irrational Beliefs Scale, multidimensional health locus of control  and health promoting lifestyle profile. The results of this study showed that a correct prediction 74.5  percent of normal-weight people and 69 percent of people with obesity classes, the model was significantly reliable (P<0/001, df= 10 and chi-square= 65/69) and in total 72 percent of the predictions were correct. Irrational health beliefs, health locus of control and health-oriented lifestyle are capable to predict obesity. It could be concluded that changing lifestyle and health locus of control could be one of the main mechanisem for overcoming the risk of being overweight and obesity.