This article presents the process of adjusting into Spanish Kenny’s Music Performance Anxiety Inventory (Kenny, Davis, & Oates, 2004). This questionnaire is based on Barlow’s theory of performance anxiety and evaluates levels of anxiety whilst on stage. After doing two translations into Spanish, a peer review, and pilot study, the questionnaire was answered by 490 musicians training in six Spanish music conservatories. Results showed that the adapted version of the instrument, with some minor modifications, has good psychometric properties, also validated through a confirmatory factor analysis procedure. Thereof, and in accordance with to Barlow’s theoretical framework, we saw emerge three related factors that made reference to specific cognitions of performance anxiety, such as helplessness as a factor of psychological vulnerability and early family influences. Performance anxiety is related to a psychological vulnerability profile and early relationship context. Finally, it is important to count with reliable instruments that allow contrasting theories in different cultural background, comparing the effects of problems or treatment outcomes.