Objective
Suicidal thoughts and behaviors (STBs) are common among medical students, but larger, diverse studies are needed, especially in low- and middle-income countries. This study aims to assess the prevalence and factors associated with STBs among Brazilian medical students. 

Methods
A survey of 1,026 Brazilian medical students gathered data on sociodemographics, STBs, depressive (PHQ-9) and anxiety symptoms (GAD-7), university stressors, learning environment, religiosity, and hazing. Prevalence and regression analyses identified associated factors, and latent class analysis (LCA) identified distinct risk groups. 

Results
Lifetime prevalence rates were 62.7% for passive thoughts of death, 39.6% for suicidal ideation, and 12.7% for lifetime suicide attempts, with 4.4% reporting at least one attempt in the past year. Anxiety symptoms were associated with all suicidal outcomes. Depressive symptoms, university stressors, and poorer learning environment were associated with higher suicidal ideation scores, while male sex and higher intrinsic religiosity were inversely associated with depressive symptoms. In the LCA, all religiosity dimensions differed significantly across classes, with the highest levels in the Low-Risk group. Hazing victimization and non-cisgender identity were associated with suicidal behaviors. LCA identified three groups: Low-Risk (42.4%) with minimal suicidal thoughts, distress, and higher religiosity; Moderate-Risk (41.1%) with intermediate levels; High-Risk (16.5%) with severe suicidal thoughts, depression, anxiety, university stress, poor environment, and hazing. 

Conclusions
Based on our findings, interventions designed to address suicidality in this population may benefit from focusing on modifiable institutional factors (learning environment, university stressors, hazing) alongside individual mental health support, particularly for minority students.