Although corporate social responsibility (CSR) research in hospitality has grown substantially, most evidence comes from large corporations in high-income countries, leaving food-service micro and small enterprises (MSEs) in emerging economies largely unexplored. This study investigated which sociodemographic and organizational factors predict operational CSR practices in 150 formal restaurants in Piura, Peru, using a quantitative, cross-sectional, associative-predictive design. Data were analyzed using IBM SPSS Statistics v.28 for descriptive, bivariate, and regression analyses, and IBM SPSS AMOS v.27 for confirmatory factor analysis. Grounded in an integrative framework combining human capital theory, institutional theory, and stakeholder theory, the study operationalized CSR through three dimensions validated for the Peruvian context: supplier relations, customer relations, and food safety. Multiple regression analysis revealed that manager academic education, certifications, and monthly sales were significant predictors, jointly explaining 23.9% of CSR variance, while firm size and service mode were not significant. Nearly all establishments scored at an intermediate CSR level, with none reaching the optimal category. Theoretically, these findings demonstrate that managerial cognitive capabilities and institutional routinization mechanisms are more powerful drivers of sustainability adoption than firm size in resource-constrained contexts. Practically, the results suggest that subsidized certification programs and targeted management training represent more efficient sustainability levers than generic business growth loans for food-service MSEs, contributing to SDG targets 8.3, 12.3, and 12.6.