PurposeThis study aims to advance a holistic and integrated view to understand the relationship between career capital and career success among knowledge workers.Design/methodology/approachThe study examines the associations of three forms of career capital – human, social and psychological capital – on career success. Career success is measured through a subjective evaluation of career satisfaction and an objective evaluation of promotion. The data are drawn from 624 knowledge workers from Finland with an academic degree in business studies. The model is tested through structural equation modeling.FindingsThe results stress the importance of psychological capital as an important career resource among knowledge workers. Therefore, our findings contribute to career research by supporting the argument that context and/or occupational group matters in the relationship between career capital and career success.Research limitations/implicationsThe cross-sectional data partly restrict our ability to delimit an impact. Further research using a longitudinal design would be required to confirm longitudinal effects. The respondents were a relatively homogeneous group of knowledge workers, and thus, the results are not generalized to other samples. The Finnish context (e.g., a high-quality education system, welfare society, dual-earner model) may also include special aspects that may have an effect on results limiting generalization to different contexts rather than Nordic ones.Practical implicationsCareer capital is an important element of taking charge of one's career, which is expected in current working life scenarios. Given psychological capital has an impact on employees' career success, employees' psychological capital could be supported in organizations to help them to adapt to career changes. Employers benefit from individuals who are willing to invest in their work, and therefore, the employers should be aware of the individual factors that affect employees' career success.Social implicationsThe meaning of career success may be context and culture related, as might its predictors. Hence, perceived career success may benefit and spill over to several stakeholders such as employers, family members and friends through its effects of positive energy and well-being. Career counselors could place more emphasis than currently on developing the psychological capital of their clients. The findings are important for other practitioners as well, such as human resource (HR) professionals who might consider dedicated programs fostering psychological capital qualities, which seem to relate to career success among knowledge workers.Originality/valueA research model that considers career capital as an integrated entity is presented rather than focusing on a single form of career capital. Contextual issues were included by focusing on knowledge workers who represent careerists in a welfare society. These findings could advance career theory and provide developmental guidelines to help employers, HR and career-oriented individuals to build successful careers.