This study examines the relationship between internal and external relational social capital (RSC) and innovation in small industrial firms in Tabasco, Mexico. The research design is non-experimental, cross-sectional, descriptive, correlational, and explanatory, using linear regression analysis. The study found significant positive relationships between internal and external RSC and innovation. Both types of RSC significantly contributed to explaining innovation. The study identified areas of opportunity for these firms, including process design and formal research activities for new raw materials, production procedures, and patent generation. The findings suggest that to promote innovation, managers of small industrial companies must continue to establish strategies and practices to strengthen RSC. The study contributes to theory and practice by providing a better understanding of the relationship between RSC and innovation, and it offers practical recommendations for small firms to enhance their relational elements and external RSC.This study examines the relationship between internal and external relational social capital (RSC) and innovation in small industrial firms in Tabasco, Mexico. The research design is non-experimental, cross-sectional, descriptive, correlational, and explanatory, using linear regression analysis. The study found significant positive relationships between internal and external RSC and innovation. Both types of RSC significantly contributed to explaining innovation. The study identified areas of opportunity for these firms, including process design and formal research activities for new raw materials, production procedures, and patent generation. The findings suggest that to promote innovation, managers of small industrial companies must continue to establish strategies and practices to strengthen RSC. The study contributes to theory and practice by providing a better understanding of the relationship between RSC and innovation, and it offers practical recommendations for small firms to enhance their relational elements and external RSC.