This paper investigates the relationship between Locus of Control and students' performance and how culture mediates the relationship. Samples of 154 international students studying Master of Professional Accounting program (MPA) at the University of Western Sydney with various cultural backgrounds were surveyed. The results revealed a significant positive relationship between performance and internal locus of control score. This reaction was better explained when the culture variable was introduced as a mediator variable. This study also showed the impact of culture on students' performance.