Abstract This paper emphasizes the role of labour demand as a determinant of human capital formation. After a section in which the alternative conceptions on the functioning of labour markets are presented and different ways of measuring human capital are compared, an applied analysis is carried out in which we provide a labour-demand-oriented measure of human capital, as defined by the amount of specific skills firms generate through work-based training (WBT) activities. By merging three rich firm-level datasets, we estimate the impact of a set of variables supposed to affect both the propensity to invest in WBT and the intensity of training within the Italian manufacturing industry over the period 2001–2005. Special attention is devoted to the variables characterizing within-firm organization of knowledge, organizational change and the formation of competence pipelines: among them, innovation, internationalization commitment, out-sourcing and new hirings. The estimates show that the effect of innovation on WBT is higher when the introduction of new technologies is supported by organizational innovations. When looking at the nature of WBT, we investigate the different determinants of the firms' propensity to provide both in-house and outside training. We measure training intensity in terms, respectively, of the number of provided training activities, private and total training costs and share of trainees.