This study examined the factor structure and scale reliability of the Motivation Sources Inventory (MSI; Barbuto & Scholl, 1998), an instrument designed to measure the motivational concepts contained within the meta‐theory of motivation (Leonard, Beauvais, & Scholl, 1999). Participants were comprised of financial‐service professionals, health‐industry administrators, and retail and distribution workers, all engaged in full‐time employment in Ireland. Data were collected through the administration of the Motivation Source Inventory (MSI) to a sample of working professionals (N = 252). Factor analyses, scale reliabilities, and inter‐item correlations were conducted. Results of the current study did not support the scale structure reported by the instrument developers. The implications of these results and suggestions for future research are presented.