ABSTRACT Objective: to understand how mental health education is developed in a nursing undergraduate course based on professors' perceptions of specific disciplines. Method: qualitative, exploratory and descriptive research, developed with 11 nursing professors of mental health disciplines, from a public university in the south of Brazil. Data collection was performed through semi-structured interview in 2014. Data were submitted to thematic analysis. Results: the following categories emerged: Training for mental health education; Specificities of teaching in mental health; and Development of practical classes / internships in mental health. Mental Health education, which prioritizes cognitive and technical aspects in line with the Psychiatric Reform, the consolidation of the Unified Health System and the implementation of the National Nursing Curricular Guidelines, becomes a challenge as the break with the teaching model and health, once in force, is current. Conclusion: this scenario highlights the need for mental health education training for nursing professors and ongoing curricular revision and pedagogical strategies.