Objective: Irritable bowel syndrome (IBS) is one of the most common gastrointestinal diseases that reduce people's quality of life and work efficiency. Studies on the prevalence of IBS in Turkey are scarce. This study aims to determine IBS prevalence and related factors among medical students in Gaziantep. Methods: The cross-sectional study was conducted at February 2021. Data were collected from students of Gaziantep University Faculty of Medicine via online questionnaire. IBS symptoms were evaluated by using the Rome IV diagnostic criteria. Results: A total of 427 (171 preclinical, 256 clinical) students were examined. The average age of the participants was 22.07 ±2.55 years and 58.1% of them were women. Sixty-nine (16.2%) students had symptoms consistent with a diagnosis of IBS. The IBS prevalence was 16.9% (n=42) among the female students and 15.1% (n=27) among the male students. The prevalence in clinical classes was 19.5% and was significantly higher than preclinical classes (11.1% p=0.021). There was a significant difference between IBS and positive family history OR: 2.57 (95% CI: 1.39-4.75), food intolerance OR: 4.14 (95% CI: 2.36-7.27), frequent sleep problems OR: 2.16 (95% CI: 1.24-3.75), not exercising regularly OR: 1.71 (95% CI: 1.01-2.91). There was not a statistically significant relationship between IBS and income, body mass index, smoking and emotional stress. Conclusion: The general prevalence was 16.2%, and it was 19.5% in clinical classes. The factors of having IBS in family history, food intolerance, sleep problems and not exercising regularly can be associated with the prevalence of IBS.