Objective: To analyze the limitations, strategies, importance and obstacles in mental health education in undergraduate nursing, focused on the role of nurses in Primary Health Care. Method: An exploratory descriptive study conducted with 103 professors in the mental health area of Bachelor/Postgraduate nursing courses from 89 public Higher Education Institutions in the five regions of Brazil. Results: Only 23.3% (24) of the professors teach mental health classes only in primary health care. Of the sample, the limitations to teaching in primary care education are few class hours (46.6%), faculty to expand teaching beyond specialty settings (38.8%), and prioritization of other scenarios (48.5%). When teaching, the strategies used are home visits (43.7%), educational actions (34.0%) and active search for mental health cases (29.1%). The professors consider them important to support mental health actions (58.3%); and the barriers are the lack of articulation between the Collective Health and Health disciplines to conduct teaching (87.5%). Conclusion: It is suggested that the institutions, courses and professors make the commitment and focus efforts to overcome the gaps, which hinder the nurse’s education process regarding primary knowledge in mental health, so that they can offer care to patients in psychological distress in the context of the community, as well as strengthen national mental health policy.