Original formulations of the Work Locus of Control Scale (WLCS) proposed a unidimensional structure of this measure; however, more recently, evidence for a two-dimensional structure has been reported, with separate subscales for internal and external loci of control. The current study evaluates the one- and two-factor models with confirmatory factor analysis. The results suggest that although the two-factor model provides a better fit of the data than does the one-factor model, it still does not reach an adequate standard of fit. Exploratory factor analysis reveal the presence of a third factor, and confirmatory factor analysis indicates that the three-factor model provides a superior fit to either the one or two-factor model. This finding is replicated with a second independent sample. These findings call into question the psychometric robustness of the WLCS and indicate that further refinement is required. (Contains 6 tables.)