Letter fluency is one of the executive function tests most frequently used to measure higher mental cognitive processes. In the present study, the influences of academic background, gender, intelligence, and the fluency aspect of creativity on letter fluency scores were evaluated. A total of 48 undergraduate students (20 males and 28 females) from two different academic backgrounds (social science and exact science) participated in this study. The results indicated that gender and academic background had no significant effect on the performance of letter fluency. On the other hand, intelligence and fluency aspect of creativity were significantly associated with the performance of letter fluency. Furthermore, the impact of intelligence on performance in the letter fluency task was fully mediated by the fluency aspect of creativity, which might suggest that the letter fluency and the fluency aspect of creativity measure the similar constructs.