Adapting to the rapidly changing business and working world today is a behavior that every individual needs, no matter what stage of their career. One of the important variables that make it easier for individuals to adapt to these changes is proactive career behaviors. Addressing the roles of the variables that strengthen proactive career behaviors within a certain approach (i.e., Social Cognitive Career Theory) will produce results that will contribute to adapting to the change that the individual needs. Therefore, the purpose of this research is to investigate the mediating role of vocational outcome expectations in the relationship between the visions about future (hope, optimism, pessimism) and proactive career behaviors. 442 university students participated in the research. The ages of the participants vary between 18-27. The structural equation modeling method was used in the analysis of the data. Results indicated that visions about future and vocational outcome expectations were positively associated with proactive career behaviors. The results also indicated that vocational outcome expectations have been shown to have a partial mediating role in the relationship between the visions about future and proactive career behaviors.