Objective: Little is known about specific professional factors influencing medical students’ suicidal ideation and behavior. We aimed to evaluate the prevalence and correlates of suicidal ideation in Tunisian medical students. Method: This was a cross-sectional study; 390 second-cycle medical students were enrolled at the Faculty of Medicine of Tunis. Participants responded to an anonymous questionnaire containing sociodemographic data, educational factors, the Suicidal Ideation Questionnaire (SIQ), and the Depression, Anxiety and Stress scales (DASS-21). Results: Eleven students (2.8%) had made one or more suicide attempts in their lifetime. For a threshold value of 41 based on the SIQ scale, 7.9% of students were considered to have a potential risk of suicide. The multiple hierarchical linear regression analysis identified as main factors independently associated with suicidal ideation: tobacco consumption, perceived sleep quality, depression symptoms, the personal history of suicide attempt, the satisfaction with student–supervisor relationship, and choosing to study medicine. Conclusion: Suicide prevention efforts should target high-risk students with prior personal or family history of suicidal behavior. Moreover, medical school authorities should put in place effective strategies to optimize the learning environment at their institutions.