Background: Mental Health(MH) is among the main determinants of community well-being and a remarkable portion of global burden of diseases is pertaining to mental disorders. Despite this fact, little attention has been given to the provision of adequate and appropriate MH services and improving equitable access to these services in some parts of the world especially in low-and middleincome countries(LMICs). This review was aimed to identify key barriers to the provision and utilization of MH services in LMICs. Methods: We carried out a systematic and comprehensive search on 7 important online databases for English-language literature on key barriers to the provision and utilization of MH services in LMICs from Jan 2000 to Nov 2019. Arksey and O'Malley instructor was used in 5 steps to implement scope study. The extracted materials were tabulated and synthesized using a qualitative content analysis approach. Results: Three main themes were developed regarding the barriers to the provision of MH services in LMICs including resource and administrative barriers, information and knowledge obstacles, as well as policy and legislation barriers. Also four main themes emerged about barriers to the utilization of MH services including attitudinal, structural, knowledge, and treatment-related barriers. Conclusion: Equitable access to MH services in LMICs is under influence of many barriers in both provision and utilization sides. In order to alleviate these problems, health systems in LMICs could adopt some strategies including integration of MH policy into general health policy, improvement of public MH knowledge regarding the MH and its related issues, developing anti-stigma programs, reallocation of health resources toward high-priority MH needs, developing community-based insurance, as well as integration of MH services into all levels of health-care systems. Further studies are also required for determining relative importance of the barriers and their related solutions based on the national context of each country.