Objective: The purpose of this study was to identify the underlying dimensions of professional suitability. Method: Data were collected from a province-wide mail-out questionnaire surveying 341 participants from a random sample of registered social workers. Results: The use of an exploratory factor analysis identified a 5-factor solution on professional suitability: social consciousness suitability, ethical suitability, practice suitability, and personal suitability, and distractors. This factor solution accounted for 47.4% of variance and achieved strong internal consistency with an overall Cronbach's [alpha] value of 0.89, and subscales values ranged between 0.89 and 0.72. Conclusion: The identified underlying dimensions of professional suitability provide groundwork for the development of a psychometrically sound instrument for assessing performance of social work students and/or practicing social workers. (Contains 2 tables.)