Background: Tension-type headache (TTH) is the most common primary headache disorder among medical students. It affects academic performance and the quality of the student's daily lives.Objective: This study aimed to investigate the prevalence of TTH and associated factors among students at King Abdulaziz University (KAU) in Jeddah, Saudi Arabia. Methods: A cross-sectional study involved students at KAU in the academic years from 4th to 6th grades during the calendar year of 2019. For sampling purposes, we adopted a stratified proportional random sampling technique, and for data collection, we used a selfadministered questionnaire. We defined TTH according to the diagnostic criteria in the third edition of the International Classification of Headache Disorders (ICHD-3b) from the International Headache Society (HIS). Results: A total of 387 medical students were approached, 50.1% were females, and 49.9% were males; their mean age was 22.8 ± SD 1.4. The lifetime TTH was 43.9%, and the 1-year prevalence TTH was 28.9%, these included both frequent TTH 25% and infrequent TTH 73%. Only 2% suffered from chronic TTH. Female sex was an unconfounded predictor for TTH, and sleeping for less than 8 hours/night was significantly associated with TTH (p<0.05). The most common aggravating factors included studying stressors (83.3%), and psychological stressors (46.5%). Conclusion: tension-type headache is a common problem among medical students. It is highly recommended to provide a stress-free study environment, stress management courses, and relaxation programs.