This study examines the relationship between internal and external relational social capital (RSC) and innovation in small industrial firms in Tabasco, Mexico. It investigates how much internal and external RSC contribute to innovation. The research uses a nonexperimental, cross-sectional, descriptive, correlational, and explanatory design, employing linear regression analysis. The results show significant positive relationships between internal and external RSC and innovation. Both types of RSC contribute significantly to explaining innovation. The study identifies opportunities for these firms in process design and formal research activities for new raw materials, production procedures, and patent generation. The findings suggest that managers of small industrial firms should continue to develop strategies and practices to strengthen RSC. The study highlights the importance of both internal and external RSC in fostering innovation. It also emphasizes the need for small firms to enhance their external RSC to improve innovation. The research contributes to theory and practice by demonstrating the significant role of internal and external RSC in explaining innovation. The study provides practical recommendations for managers and policymakers to support innovation through the strengthening of RSC. The research instruments were validated for reliability and validity, making them suitable for future studies. The study underscores the importance of relational social capital in driving innovation in small industrial firms.This study examines the relationship between internal and external relational social capital (RSC) and innovation in small industrial firms in Tabasco, Mexico. It investigates how much internal and external RSC contribute to innovation. The research uses a nonexperimental, cross-sectional, descriptive, correlational, and explanatory design, employing linear regression analysis. The results show significant positive relationships between internal and external RSC and innovation. Both types of RSC contribute significantly to explaining innovation. The study identifies opportunities for these firms in process design and formal research activities for new raw materials, production procedures, and patent generation. The findings suggest that managers of small industrial firms should continue to develop strategies and practices to strengthen RSC. The study highlights the importance of both internal and external RSC in fostering innovation. It also emphasizes the need for small firms to enhance their external RSC to improve innovation. The research contributes to theory and practice by demonstrating the significant role of internal and external RSC in explaining innovation. The study provides practical recommendations for managers and policymakers to support innovation through the strengthening of RSC. The research instruments were validated for reliability and validity, making them suitable for future studies. The study underscores the importance of relational social capital in driving innovation in small industrial firms.