Nowadays, urbanization and machine-based life have been accompanied by consequences such as stress, anxiety, and depression, and forest parks, play a vital role in promoting mental health. However, the development and maintenance of these spaces face numerous challenges. The aim of this review article was to identify and categorize the challenges and strategies for the development of forest parks with an emphasis on mental health promotion based on studies conducted in Iran and worldwide. This review was conducted on 28 studies (16 domestic and 12 international studies). The findings showed that forest parks play an effective role in promoting mental health by reducing stress hormones, improving mood, increasing social interactions, and providing multi-sensory experiences. The most important identified challenges include: weak inter-sectoral coordination and lack of financial resources, poor accessibility and neglect of the visibility and sensory dimensions of green space, inequality in the distribution of green spaces and insecurity especially for women, inappropriate distribution of allergenic trees, and increased psychological pressure during crises such as COVID-19. In contrast, effective strategies include: increasing the visibility and proximity to green space, multi-sensory-based design, integration of water and greenery, development of green infrastructure with an emphasis on spatial justice, construction of special spaces for vulnerable groups (women, the elderly, immigrants). The final conclusion is that forest parks are not an urban "luxury" but a public health necessity. Overcoming the challenges requires a transition from a decorative to a therapeutic perspective, a shift from quantity-oriented to quality-oriented approaches in research, the formulation of a national guideline for the design of therapeutic green spaces, and the establishment of a single inter-sectoral trustee at the national level so that forest parks can effectively contribute to the promotion of community mental health as the "green pharmacies" of modern cities.