Background: Community health workers (CHWs) are increasingly deployed to support mothers' adoption of healthy home practices in low- and middle-income countries. However, little is known regarding how best to train them for the capabilities and cultural competencies needed to support maternal health behavior change. We tested a CHW training method, Sharing Histories (SH), in which CHWs recount their own childbearing and childrearing experiences on which to build new learning. Methods: We conducted an embedded cluster-randomized trial in rural Peru in 18 matched clusters. Each cluster was a primary health facility catchment area. Government health staff trained female CHWs using SH (experimental clusters) or standard training methods (control clusters). All other training and system-strengthening interventions were equal between study arms. All CHWs conducted home visits with pregnant women and children aged 0-23 months to teach, monitor health practices and danger signs, and refer. The primary outcome was height-forage (HAZ)<-2 Z-scores (stunting) in children aged 0-23 months. Household surveys were conducted at baseline (606 cases) and 4-year follow-up (606 cases). Results: Maternal and child characteristics were similar in both study arms at baseline and follow-up. Difference-in-differences analysis showed mean HAZ changes were not significantly different in experimental versus control clusters from baseline to endline (P=.469). However, in the subgroup of literate mothers, mean HAZ improved by 1.03 on the Z-score scale in experimental clusters compared to control clusters from baseline to endline (P=.059). Using generalized estimating equations, we demonstrated that stunting in children of mothers who were literate was significantly reduced (Beta=0.77; 95% confidence interval=0.23, 1.31; P<.01), adjusting for covariates. Conclusion: Compared with standard training methods, SH may have improved the effectiveness of CHWs as change agents among literate mothers to reduce child stunting. Stunting experienced by the children of illiterate mothers may have involved unaddressed determinants of stunting.