Recently, various studies have suggested that ethical leadership offers an important antecedent of fluid internal workplace relationships, which are conducive of internal social capital. Yet existing research has neither inquired into potential mediators of this relationship nor addressed the role of other distinct leadership strategies in encouraging such a valuable capital. This study advances previous research by examining if servant leadership, which seeks to put followers’ interests and needs first, can account for social capital variance within the work group, which (...) is the building block of organizations. New to the literature, we also investigate whether group citizenship behavior mediates this relationship. A sample of 352 work groups, spanning 187 hotels located in Spain, reveal that group citizenship behavior partially mediates the positive influence of servant leadership on group social capital. Managers can use these findings to lead their businesses in a more socially friendly direction while also building group social capital, which can improve the competitiveness of their work groups, and the entire business. (shrink)