This article tries to provide a specific analytical framework which includes labour as an essential factor within die internal and external set of relations defining the competitiveness of firms and their strategies to adapt to the environment in which they operate. Special attention is given to the Spanish case, taking into consideration its regional and sectorial diversity. Instead of studying labour as an input to be bought and applied, or the history of the conflict between employers and employees, this article analyses the evolution of how different forms labour have been organised within firms. Labour is considered as an element with the potential to provide an incentive, to impede, facilitate, delay, and mainly adapt technological change to the different factor endowments. The emphasis is put on human capital —mainly shopfloor skills, organisation skills and research skills— instead of physical capital to explain the competitiveness of firms. Special attention is reserved to the institutional context and the interaction between business and governments on labour issues, analysing the state as an employer, regulator and intermediary in the transmission of skills and knowledge.