Knowledge has been broadly recognized as the key element for gaining competitive advantage. Companies are investing more on knowledge management systems. However, no models are customized to evaluate the success of knowledge management systems. To address this issue, this study seeks to develop and test two models for the assessment of the success of a particular type of KMS: project repositories. These two models are based on DeLone and McLean’s model of Information Systems Success and Seddon’s respecified model. Their models are updated for project repositories through the addition of three relationships.