the purpose of this research was to design a structural equation model to identify relationships between psychological capital (optimism, hope, resilience and self-efficacy) and knowledge sharing behavior in a sample of 137 professional employees in bogotá stratified by demographic variables. two instruments were used: the pcq (psycap questionnaire), developed by luthans, youssef and avolio (2007a) that measures psychological capital and was duly translated into spanish and adapted linguistically and culturally to the population under investigation, and the subscale to measure knowledge sharing behavior by casta？eda and fernández (2008). results confirmed the seven proposed hypotheses and showed significant positive correlations between psychological capital, its four components and the behavior of knowledge sharing. furthermore, it was found that the construct of psychological capital has greater potential to explain knowledge sharing behavior than its four separate components. the discussion presents numerous opportunities for research on this topic in the future.