People with a non-Western migration background living in Western countries are more likely to experience psychiatric problems and have more severe symptoms when they do. Patients of non-Western origin also have more unmet needs for care. This study focuses on differences between Western and non-Western patients in care needs being met during the course of mental health treatment. The care needs of 1099 patients, 39% with and 61% without a non-Western migration background, recorded between 2017 and 2020 in Flexible Assertive Community Treatment, were compared. Non-Western migrants more often received psychotic disorder diagnoses, had more socio-economic problems, met, unmet and total needs for care and experienced less reduction in unmet needs during treatment. This was specifically the case for the rehabilitation areas: daily activities, treatment information, basic education, paid work and meaningful life and recovery. After controlling for socio-economic factors and diagnosis, group differences in change in number of unmet needs were no longer significant. However, the reduction in unmet needs in the areas of basic education, paid work and meaningful life and recovery remained significantly smaller for non-Western patients. Except for the rehabilitation domains of basic education, paidwork and meaningful life, the disadvantages in resolving the care needs of patients with a non-Western migration background do not remain significant after taking into account socioeconomic factors and diagnosis. Collaboration of mental health care and the social domain is warranted to improve socio-economic factors for patients with a non-Western migration background, to better address their unmet needs for care.