In the Brazilian contemporaneous context, there is evidence of society's demands for companies to carry out their activities in a responsible manner in the social and environmental spheres. In the coal mining industry, the debate is even more eminent because of the significant environmental impacts generated by the mining activity. The present study aims to analyze the determinants of socio-environmental practices of coal companies in the South of Santa Catarina (SC) and Rio Grande do Sul (RS) in the perceptions of company managers and institutions by these actions, under the perspective of social capital. The research is empirical and is supported by a descriptive qualitative approach, using documentary analysis and interview as a data collection technique. From the point of view of the research strategy, it consists of a multicase study. Managers from two national and private capital companies were interviewed, with importance on their economic area in SC and RS, respectively: Copelmi Mineração Ltda and Carbonífera Catarinense Ltda. Managers of two institutions benefited by the actions of the respective companies, which characterize social-environmental responsibility related to theories of social capital. The results demonstrated empirical evidence of social capital constituted in the existence of networks of relationship between the companies and the institutions impacted with focus on the reciprocity. It was detected that the synergy among those involved, as a motivation for social and environmental actions, produces improvement in the search for quality of life and in the training of the impacted.
Key words: Social responsibility, social and environmental actions, social and environmental determinants, share capital, social actions.