This article presents the results of a study aimed at constructing and validating a scale for measuring the professionalization of health sciences students. Evidence of the content, response process, and internal structure of the scale was provided throughout the study, including data collection from 561 undergraduate and graduate students from four Quebec universities. The results of an exploratory factor analysis indicated a very good internal consistency and support for a simple four-factor structure. Thus, a fourth factor (valuing the profession) was added to the three factors (professional skills, identity, and culture) set out in an initial conceptual framework. The results of a confirmatory factor analysis revealed that these four first-order factors were related to a single second-order factor of professionalization. This scale provides a robust instrument that can be used for studying the professionalization of students at different phases of their educational journey.