This study compared factor structures of the Occupational Work Ethic Inventory (OWEI) for self-perceived work attitudes of manufacturing employees and their supervisors' ratings of those same employees. The purpose of the study was to evaluate construct validity through comparative factor analysis. Four factors were generated through principal components analysis and compared across the groups using the Coefficient of Congruence, the Salient Similarity Index, and the Root Mean Squares methods for comparing factors. Results indicated that the factors measured by the OWEI were virtually the same, for both groups, providing evidence of construct validity for this instrument.