The Ten Item Personality Inventory (TIPI) is a widely used instrument based on a personality framework measuring five dimensions: Extraversion, Agreeableness, Conscientiousness, Emotional Stability, and Openness to Experiences. The aim of this study was to establish a scale to assess dental students’ professionalism by adding to the TIPI’s five dimensions a set of descriptors that define professional behavior in dental students. The resulting Patient Management and Professionalism Scale (PMPS) was then tested with a cohort of graduating students at the University of Michigan School of Dentistry. To develop the scale, one clinic director and a patient care coordinator from four clinics wrote descriptive statements for each of the five dimensions based on their observations of dental students in the context of their clinical experiences. These descriptors were compiled into a single scale. The PMPS demonstrated good scale reliability and interrater agreement and correlated significantly with students’ patient management grade scores and cumulative GPA at the end of their fourth year. Exploratory factor analysis showed the presence of a single factor (professionalism) with all five dimensions loading highly on this factor, accounting for 66% of variance in scores. While a useful standardized measure to assess professionalism in dental students, the PMPS also has a flexible format that makes it easy for other schools to use.