This paper explores the role of social integration mechanisms for knowledge absorptive capacity (ACAP) in southern Brazilian firms. We followed a positivist approach and we used quantitative methods. Our sample includes 125 firms from Southern Brazil. Hypotheses were tested using structural equation modelling (SEM) supported by the software ADANCO 2.0.1. Our paper contributes to the knowledge-based view literature by contributing to understand ‘why’ and ‘how’ social integration mechanisms are influencing knowledge absorptive capacity in firms. Our results suggested that social integration mechanisms have a positive effect on ACAP dimensions, and that the use of teams that are cross-functional and composed by people with diverse background, is likely to improve ACAP capabilities in firms. We suggest that further studies may perform a deeper analysis about the moderation effect of social integration mechanisms on ACAP. By identifying the relevance of social integration mechanisms for improving ACAP, this study brought valuable information to managers of both Brazilian firms and foreign organisations willing to establish their operations in Brazil, for the efficient allocation of firm resources for improving the innovative performance.