ABSTRACT Background Globally, one of the major problems facing health systems is an acute deficit of health workforce. To ensure equitable distribution and deployment of health workers, up-to-date and timely information on the health workforce is vital. Health workforce registries (HWRs) have the potential to generate data for evidence-based human resource planning and policies. There is a lack of evaluative research on the capacity of HWRs to improve health systems. This review aims to assess the effectiveness of HWRs for improving health systems in low- and middle-income countries. Methods We searched selected electronic databases from inception to 14 April 2020. Two authors independently screened studies and extracted data from included studies. We presented results as a narrative synthesis. Results We included eight studies of moderate–high quality in this review. The results suggest that HWRs can improve the distribution and skill-mix of the health workforce, quality of health workforce data, availability and use of data for policy and planning, and user satisfaction. The evidence was derived from case studies, which limited our ability to infer a causal relationship. Conclusion More rigorous research from controlled experimental studies is needed to consolidate the available evidence from observational studies.