This qualitative study explores the reflexive relationships among mental illness, acculturation, and progress toward English proficiency in five adult immigrants being treated at a Canadian psychiatric hospital. The research explores the additional challenges faced by mentally ill individuals when learning a new language and the extent to which English language acquisition may be impeded by factors related to mental illness. Semistructured ethnographic interviews are conducted with the patients. Data analysis is accomplished through grounded theory methods, specifically data-driven and theory-driven coding. The English language acquisition experiences of these five individuals are contrasted with second-language acquisition theory to suggest that the effects of the theoretical language learning advantages possessed by this group may have been diminished by factors related to mental illness. Policy recommendations are made to address this additional set of challenges for immigrants with psychiatric disorders.