Adults with mental illness may experience a higher incidence of dysphagia and choking due to factors such as medication side effects and behavioural abnormalities. The aim of this study was to determine the frequency of dysphagia and the most effective interventions for this population. Studies published up to August 2010 were sought via a comprehensive electronic database search (CINAHL, PsycINFO, MEDLINE, PubMed, Cochrane, and Embase). Studies reporting dysphagia frequency or dysphagia intervention outcomes in adults with mental illness were included. Two reviewers independently assessed study eligibility and quality, and the results were synthesised descriptively. Ten studies were identified, each describing dysphagia frequency or death due to choking asphyxiation. No studies evaluating intervention effectiveness were identified. Study quality was limited by subjective assessment of outcomes. Six studies presented dysphagia frequencies ranging from 9 to 42% in varying subgroups. Four studies presented the frequency of choking asphyxiation death, including a large survey that concluded that adults with organic mental illness were 43 times more likely to die of this cause than the general population. Dysphagia is a common and significant cause of morbidity and mortality in adults with mental illness and our review found that there is a lack of studies evaluating the effectiveness of intervention techniques.