Enterprise resource planning (ERP) systems implementation success factors have been widely researched; however, few have investigated ERP post-implementation success in organizational contexts. The paucity of research into ERP system success evaluations partly motivates this research. To that end, the objective of this study is twofold. First, it primarily investigates the relationships among six constructs or dimensions in a respecified ERP system success measurement model, which was developed from prior relevant frameworks. Second, this research adds to the body of knowledge in the information system (IS) success evaluation domain, especially with its focus on ERP packages. The extended ERP system success model was tested using data collected in a cross-sectional field survey of 109 firms in two European countries. Structural equation modeling (SEM) was used to test six relevant hypotheses. The SEM results showed that five out of the six hypotheses have significant, positive associations. Namely, the constructs of System Quality, Service Quality, Individual Impact, Workgroup Impact, and Organizational Impact have strong relevance in ERP success conceptualization, whereas Information Quality does not, at least, in the context of our data. The pertinence of the study's findings for IS success evaluation as well as its implications for practice and research are discussed.