We present an analysis of the dimensionality of the scales that assess the nine team roles contained in the Team Role Self-Perception Inventory. Using a data set of over 14,000 respondents, reasonable fit to seven-item unidimensional factor models was obtained for all scales except Implementer and Specialist. Two-factor structures for all scales showed improvements in model fit although for all roles a small and unreliable second factor was found. Bi-dimensional structures reflect the separate loading of negatively worded items and/or different item content areas. Five-item scales provide a more economical version of the inventory and areas for further development of the instrument are identified.