Preproject phase is an important but often ignored research area in information systems field although it has an undeniable importance for successful project. The purpose of this study is to identify factors affecting project performance in preproject phase and to find empirically critical factors among them. After deriving 9 factors through literature review including clear project definition, project leader position, staffing efforts, preproject team expertise, preproject knowledge scope, preproject partnering, top-management support, resource sufficiency, and project climate, the study investigate the influence of those factors on project performance. The study results reveal that clear project definition, project climate, resource sufficiency, pre-project knowledge scope, project leader position have significant impact on project process satisfaction, a measure of project performance, but the other factors do not. Based on the empirical results, the study discuss academic and practical implications.