Armed conflicts and other humanitarian crises impact mental health and psychosocial wellbeing. In contexts of overwhelming need and overstretched government health systems, nongovernmental organisations may play important roles. In this paper, we respect on the role of Nepali nongovernmental organisations in providing mental health and psychosocial support services. In Nepal, nongovernmental organisations have provided a range of trainings, implemented interventions, organised awareness raising campaigns and conducted research on mental health and psychosocial issues in the context of political violence and natural disasters. Some have been able to capitalise on the emerging interest of humanitarian donors in mental health to strengthen the platform for sustainable mental health reforms. Nongovernmental organisations taking on such tasks have demonstrated strengths as well as presented challenges. Strengths included easy access to local communities, better understanding of local contexts, quick and flexible response mechanism and access to marginalised populations and underserved areas. Challengeshave included a lack of programme sustainability, weak collaboration and high staff turnover. Similarly, due to a lack of accreditation of training courses and rigorous monitoring of services, it has been difficult to independently verify the quality of services provided by nongovernmental rganisations. Based on observations, the authors highlight the importance of: the integration of mental health into the broader humanitarian, health and social systems; strong partnerships with governments; strong alliances between nongovernmental organisations for more elective advocacy with policy makers; a focus on monitoring, evaluation and research; standardisation of training curriculums and clinical services; and a focus on anti-stigma interventions.