This research aimed to examine the mediating role of forgiveness in the relationship between vengeance and tranquility. 297 university students participated in this research. Scales of revenge, forgiveness and tranquility were used to collect data. The results indicated that forgiveness played a full mediator role in the relationship between vengeance and tranquility. In other words, in this model, as vengeance increases, tranquility and forgiveness decrease, and forgiveness plays a mediating role in that relationship. Individuals with high levels of vengeance are unlikely to have high levels of tranquility and forgiveness. If individuals feel more vengeance, they may have low forgiveness and exhibit less tendency to feelings of tranquility.