The main objective of this study was to analyze the influence of Positive Psychological Capital on the performance of the Portuguese Air Force Academy students. Thus, the relation between these two variables was analyzed, adding work engagement as a mediator. In this way, Positive Psychological Capital promotes Work Engagement, which in consequence leads to better performance by students. The performance variable was analyzed through task performance, contextual performance, and counterproductive work behaviors. A cross-sectional correlational study was conducted with a quantitative methodology, through a questionnaire survey. The sample consisted of 242 students. Results confirmed the existence of a positive and significant relation between Positive Psychological Capital and Work Engagement, with Individual Work Performance. Regarding the three components of Individual Work Performance there was a positive and significant relationship between Positive Psychological Capital and Work Engagement with task and contextual performance, and negative and significant with counterproductive work behaviors. It was possible to confirm that Work Engagement plays an important role in the relationship between Positive Psychological Capital and Individual Work Performance. This research has expanded the knowledge of variables that lead to better performance levels in students of the Air Force Academy. Providing the necessary information so that, efforts can be invested to amplify these levels.