Abstract. The paper describes an empirical study to investigate the state of practice and challenges concerning some key factors in reusing of in-house built components. It also studies the relationship between the companies' reuse level and these factors. We have collected research questions and hypotheses from a literature review and designed a questionnaire. 26 developers from three Norwegian companies filled in the questionnaire based on their experience and attitudes to component reuse and component-based development. Most component-based software engineering articles deal with COTS components, while components in our study are in-house built. The results show that challenges are the same in component related requirements (re)negotiation, component documentation and quality attributes specification. The results also show that informal communications between developers are very helpful to supplement the limitation of component documentation, and therefore should be given more attention. The results confirm that component repositories are not a key factor to successful component reuse.