This research aims at studying the relationships between personality traits and academic achievement among students. Participants were 285 students (191 female and 94 male). Instruments used were NEO Big Five Personality Factors and student's GPA. Results revealed personality traits were significantly related to academic achievement. Stepwise regression analysis indicated personality characteristics accounted for 48 percent of variance in academic achievement. Results also showed conscientious, which explained 39 percent of variance in academic achievement, was the most important predictor variable. Finally MANOVA and t-test indicated there is no significant gender differences in the personality characteristics and academic achievement.