Background: The relationship between sleep patterns and academic performance has been a subject of considerable interest in the field of education. However, there is a notable gap in the literature concerning medical students, who are often among the highest-achieving university students and may have distinct sleep patterns. 

Objectives: This study aimed to examine the immediate impact of the number of hours slept the night before an exam on performance the following day, with an additional focus on potential differences in this effect between genders.

Design and methods: This is a prospective self-administered questionnaire-based study. The participants were medical students at University Kurdistan Hewler. Erbil, Iraq. with a cohort of 250 medical students. It was a single-blinded study; thus, the students were asked to fill a questionnaire form at the end of their exam session, but they were not informed about the objective of the study.

Students' responses were collected over several days during the final theory exams, covering various classes and subjects in June 2023 following the receipt of ethical approval from the school.

Results: The study observed a significant positive correlation between the number of sleeping hours and exam scores. Furthermore, gender-based differences in sleeping hours and exam performance showed that female students exhibited both fewer sleeping hours and lower exam scores compared to their male counterparts. 

Conclusion: This study provides valuable insights into the importance of adequate pre-exam sleep, particularly for medical students.