Determining the relationship between insomnia and developing mental symptoms is the objective of this study. Its method consisted of a cross-sectional design study, in which a survey of medical students belonging to the International Federation of Medical Student Associations of Mexico (IFMSA) was conducted. The instrument was validated with Cronbach's alpha coefficient = 0.92. The presence of symptoms related to insomnia, sleep quality and mental disorders were evaluated. Data analysis was carried out through descriptive and inferential statistics, with a power level of p 0.05. Out of 4,576 medical students, a sample was obtained by simple randomization with a total of 401 students (42.89% men, 57.11% women) who participated in 48 medical schools. The three most prevalent symptoms found in students were: 25.19% of major depressive disorder (MDD), 18.95% of generalized anxiety disorder (GAD), and 13.22% of obsessive-compulsive disorder (OCD). Results showed that symptoms of GAD and social phobia (SAD) presented the highest correlation with insomnia. MDD was associated with poor sleep quality (RN = 14.78 95% CI: 1.97-111.04). Therefore, medical students run the risk of incurring on mental disorders if there are disturbances in their sleep. In that case, pedagogical interventions will be required to treat this problem.