Background Low medication adherence is a significant challenge in all medical fields and particularly in mental health treatment, where a lack of insight into one's own disease can repress the ability to adhere. In recent years, the increase in migration combined with a high prevalence of mental illnesses among migrants and the possible consequences of nonadherence, point towards the need for a focus on adherence with psychotropic drugs among migrants. Aim To review current literature, exploring the potential impact of being a migrant from a non-Western country living in a Western country on the level of adherence to psychotropic medication and subsequently to discuss these findings. Methods A systematic review of studies investigating adherence among non-western migrants was conducted. The literature search was conducted using PubMed and Embase databases in October 2020. Results Seven observational studies were included, all ranging from moderate to high-quality. Six out of seven studies found an association between being a non-Western migrant in a Western country and low adherence to psychotropic drugs. Conclusion Studies indicate an association between being a non-Western migrant in a Western country and low adherence to psychotropic drugs. None of the included studies investigated possible causes of the low adherence in migrants. Communication difficulties are, however, considered possible barriers to healthcare access and a contributing factor to nonadherence. There is a need for studies assessing the possible impact of interventions aiming at increasing adherence such as intercultural mediators and training of healthcare providers in cultural competencies.