Background/AimsStudies investigating the effect of occupational therapy in mental health are few. This scoping review aims to identify, present and assess studies that have investigated the effect of occupation- and activity-based/focused interventions performed by occupational therapists in mental health.MethodsThe scoping review involved searching six databases, covering articles from 2003 to 2018. ‘The Matrix Method’ was used to describe and synthesise the content of the included studies. The Oxford Level of Evidence was used to rank the evidence, and The Critical Appraisal Skills Programme was used to assess the quality of the study.ResultsA total of 21 original studies and 4 systematic reviews were included in this review. Interventions, approaches, programmes, training, and activities such as cooking, artwork, crafts, pottery, sports, calligraphy, horticulture, and music, organised individually or in groups, were investigated in the included studies. Individualised occupational therapy showed clinically significant improvements in social functioning and cognition, promising results were found on supported employment and education.ConclusionsFew high-quality studies that have investigated the effect of occupation-and activity-based/focused interventions performed by occupational therapists in mental health were found. This scoping review highlights the importance of future high quality studies to support evidence-based practice within mental health occupational therapy.