SummaryThe discriminant validity of perceptions of organizational politics, organizational support, and procedural and distributive justice was examined as the distinctions between these variables have been blurred in past research. Results from a sample of 418 full-time employees provided evidence of discriminant validity for these variables. First, structural equation modelling was used to isolate the best structural representation of these four variables. Then, six theoretically relevant predictors (i.e., leader±member exchange, centralization, formalization, co-worker cooperation, role con¯ict, and locus of control) were examined in an effort to provide further conceptual separation. Five of the six antecedents distinguished among politics, justice, and support. Suggestions for additional research that can shed light on the distinctions and similarities of these variables are offered based on the results of this study.