Background: Mental health problem is the major health problem globally and nationally in Ethiopia. To address this problem the Ministry of health of Ethiopia integrated mental health services in to the community health service. However, the preliminary reports showed the service has not been implemented yet. Therefore, the aim of this study was to explore the barriers and facilitators of mental health service implementation in to the Ethiopian health extension program.Methods: A qualitative case study was conducted in the Ethiopian primary health care system from 12 August to 25 September 2019. We have conducted about ten purposively selected key informant interviews from the Ministry of Health and community level workers (i.e. health extension workers). All interviews were recorded using voice recorder and transcribed verbatim and translated for analysis. The data then analyzed manually in relevant themes. Results: Mental health problem currently is a major health issue in Ethiopia. However, the service is not ready to respond for the existing health service need. The recently designed integration of mental health services in to health extension program was not implemented so far. The basic identified barriers were, low political commitment, shortage of resources, non-functional referral system, lack of interest from private health service organizations, attitudinal problems from both the society and service providers, the lack of reporting system for mental health problems. On the contrary, there are also facilitators for the service like well-designed primary health care system, trained health extension workers, changing political commitment and attitude of the community.Conclusion: Although mental health problems are widely spread and increasing in alarming rate, in Ethiopia, the existing health system is not capable enough to respond. This problem is complex and intertwined. A series of activities to solve the major barriers are expected especially from the health system leaders to implement follow up and evaluate mental health services at the health extension programs.