BACKGROUND: Anemia is highly prevalent particularly in low- and middle-income countries. Iron deficiency contributes to an estimated 50% of anemia cases. Iron interventions have become central to global anemia treatment and prevention; however, few iron interventions have been scaled up to the national level, despite their proven effectiveness. While both cross-sectional and interventional studies on the effect of anemia and iron supplementation on worker productivity have been conducted, there have been few systematic reviews conducted. As such, a synthesis of previously conducted primary research is warranted and may provide a more comprehensive overview of the strength of currently available evidence, potentially helping to inform national policy on matters relating to funding and legislation for population-level iron interventions. OBJECTIVES: The objective of this study was to synthesize available evidence on the effect of both anemia and therapeutic iron interventions on productivity in working adults. METHODS: All relevant English language studies were systematically obtained from both MEDLINE and EMBASE and assessed for evidence of differing productivity levels across groups stratified by iron intervention or anemia status. Potential mediating variables were reported, and the results were narratively summarized. RESULTS: The available data from 12 included studies provide strong evidence that anemia negatively impacts occupational performance and that therapeutic iron interventions can yield substantial productivity gains. CONCLUSIONS: Despite their limitations, these findings make an important contribution to the literature highlighting the impact of iron deficiency and population-wide iron interventions on work productivity and occupational performance.