To cross-validate an instrument to measure behavioral aspects of professionalism in pharmacy students using a rating scale that minimizes ceiling effects. Seven institutions collaborated to create a 33-item assessment tool that included 5 domains of professionalism: (1) Reliability, Responsibility and Accountability; (2) Lifelong Learning and Adaptability; (3) Relationships with Others; (4) Upholding Principles of Integrity and Respect; and (5) Citizenship and Professional Engagement. Each item was rated based on 5 levels of competency which were aligned with a modified Miller's Taxonomy (Knows, Knows How, Shows, Shows How and Does, and Teaches). Factor analyses confirmed the presence of 5 domains for professionalism. The factor analyses from the 7-school pilot study demonstrated that professionalism items were good fits within each of the 5 domains. Based on a multi-institutional pilot study, data from the Professionalism Assessment Tool (PAT), provide evidence for internal validity and reliability. Use of the tool by external evaluators should be explored in future research.