Cesarean delivery continues to increase due to various reasons, considering its negative effects, our aim in this research is to investigate the behavioral intention of pregnant women who choose vaginal delivery. In this regard, the expanded Theory of Planned Behavior was used by increasing two predictor variables. About 188 pregnant women voluntarily participated in this research in some healthcare centers in Tehran County, Iran. Our results showed that this enhanced model can increase the power of the original theory. Overall, the expanded model successfully described the mode of delivery among Iranian women and explained 59.4% of the variation in the intention variable with a stronger effect. The effect of the variables added to the model was indirectly significant. Among all the variables, attitude showed the best effect on the choice of normal vaginal delivery, and after that, the variable of general health orientation had a greater effect on attitude.