The study of career paths within organizations is an issue that has received strong attention in the theoretical literature of organizational economics and management1. From the empirical point of view, however, research in this topic is scarcer and less comprehensive. The gap has been caused to a large extent by the unavailability of data tracking worker's career moves in employee-level surveys and by the lack of information about career management policies in firm-level data. This thesis contributes to fill such hole. It investigates how workers' careers and their behavior as managers depend on the characteristics of the firms where they work and their own personal characteristics, with a strong emphasis in the role of human capital. The research is carried out using micro data at both worker and firm level, available only in relatively recent data sets. The interaction between accumulation of human capital and workers' employment horizons has been frequently recognized as a key issue in explaining why some firms maintain long-term relationships with their employees while others remain closer to what it could be considered spot-market labor contracting. There are nonetheless important factors that have been usually absent in the literature of organizations. This is the case of internal firm structures that may improve or discourage the interactions between different hierarchical levels, affecting eventually to the costs of job change involved in promotions. Both human capital and organization-relational aspects of career paths are objects of study of this thesis. First, it is analyzed how the characteristics of employers and the markets where they work affect the general or firm-specific nature of employees' human capital and, therefore, to the type of employment relationship held. Second, it is investigated how differences in employees' personal characteristics affect their career horizons, the management of their human capital and the type of career moves done. Finally, the effects of these factors on career path outcomes are examined, in terms of leadership behavioral differences among those arriving at managerial levels. A particular attention is paid the important differences between the careers of men and women that are also found in their managerial style. Overall, the research presented here sheds light on what career management schemes adapt better to different product and labor market circumstances. It opens as well a number of challenges for the study of human resources management and shows that population-wide surveys can be very useful tools to carry out empirical investigations in this area, usually dominated by narrower and less representative surveys.