ABSTRACT Several studies have sought to identify the factors that are associated with successful KMS (knowledge management system) projects. Such KMS success models, however, disagree on which factors to include. To advance this knowledge, the present study uses a grounded theory approach involving interviews with NPD (new product development) professionals at 24 companies. The data analysis identifies 46 success factors, which are organized into 19 dimensions under eight categories. Using these dimensions and categories, a KMS success model is developed. The study provides two main contributions: (1) a more detailed account of factors influencing KMS success, and (2) the identification of four overall characteristics that set KMS projects apart from other enterprise information system projects. The detailed account of the conditions for KMS success provided by the present study may support the design of future KMS studies by clarifying the variables that need to be considered.