Objectives The primary objective was to measure the effect of psychiatry rotation in students self-confidence (SC) for managing mental health (MH) issues. Methods An eighteen questions version of “Preparation for Hospital Practice Questionnaire” (PHPQ) adapted for MH was applied before, after and six months later the psychiatry rotation. Sociodemographic and experience with mental illness was measured as confounding factors. Results Hundred and ten students were recruited and four factors were identified: “Diagnosis elaboration and basic care” (F1), “Crisis management and prevention” (F2), “External sickness determinants” (F3) and “Personal distress with clinics” (F4). Cronbach Alpha ranged from 0.71 to 0.90. Previous MH training were not frequent (9.09%), and associated with better SC in F2 (after p < 0.05, 6m p = 0.03). Previous mental disorder was frequent (42.16%), and associated with more SC on F2 (p < 0.01) and F3 (p = 0.03) before course, but only on F3 after (p < 0.01) and not 6 months later. Male gender had more SC in F4 (p < 0.01) before course, but after course and 6m later female gender became more SC in F1 (after p = 0.02, 6m p = 0.01) and equivalent in F4. All factors had higher scores after and 6 months later (p < 0.001). The class considered that an interview script is very important for their SC, and improves assistance (mean > 9.0/10.0). Conclusion Obligatory rotation in MH improved SC in students. Previous training and gender were related with long lasting effects in SC.