Personal initiative characterizes people who are proactive, persistent and self-starting when facing the difficulties that arise in achieving goals. Despite its importance in the educational field there is a scarcity of measures to assess students' personal initiative. Thus, the aim of the present study was to develop a questionnaire to assess this variable in the academic environment and to validate it for adolescents and young adults. The sample comprised 244 vocational training students. The questionnaire showed a factor structure including three factors (Proactivity-Prosocial behavior, Persistence and Self-Starting) with acceptable indices of internal consistency (ranging between α = .57 and α =.73) and good convergent validity with respect to the Self-Reported Initiative scale. Evidence of external validity was also obtained based on the relationships between personal initiative and variables such as self-efficacy, enterprising attitude, responsibility and control aspirations, conscientiousness, and academic achievement. The results indicate that this new measure is very useful for assessing personal initiative among vocational training students.