AbstractPeripartum severe mental disorders (PSMDs) encompass schizophrenia, affective psychosis, and psychotic and non-psychotic forms of bipolar disorders. PSMDs are well documented in high-income countries. However, much less is known about the prevalence of PSMDs in low- and middle-income countries (LMICs). The aim was to review the available literature systematically and estimate the prevalence of PSMDs among women in LMICs. We searched the Ovid MEDLINE, Embase, PsycINFO, CINAHL and Maternity and Infant Care databases systematically from the date of inception to Dec 31, 2020, for English-language publications with data on the prevalence of PSMDs among women in World Bank–defined LMICs. Selection of studies, extraction of data and assessment of study quality were each undertaken independently by at least two of the investigators. A total of five studies (completed in three countries spanning two continents) met the inclusion criteria. Five studies reported cumulative incidence of postpartum psychosis (ranging from 1.1 to 16.7 per 1000 births). We found no studies on the prevalence of severe mental disorder during pregnancy in these settings. Marked heterogeneity in methodology precluded meta-analysis. These findings indicate that PSMDs occur at a similar prevalence in low- and middle-income to high-income countries. However overall, there is a paucity of high-quality evidence from these settings. There is a need for rigorous studies with standardized methods to increase knowledge of the nature, prevalence, and determinants of PSMDs among women in resource-constrained LMICs to inform policies, service development, program planning and health professional training.