This paper sets out a taxonomy of the main factors influencing knowledge transfer (KT) between new product development (NPD) teams, based upon a sociotechnical approach whose framework consists of personnel, technological, work design, and external environment subsystems. The taxonomy was constructed from a literature survey combined with: (1) interviews and focus groups conducted with NPD experts and (2) a principal component analysis applied to a survey of 82 companies. Such steps were necessary because of the large amount of data collected from the literature review. They combine extensive explanatory descriptions from qualitative analysis together with strong confirmatory results given by multivariate quantitative analysis. The final set of 16 main factors summarized more than 100 elements of the NPD environment that influence KT between NPD teams. The key contributions of the proposed taxonomy are: (1) It is the first proposal of an organized understanding about KT influence factors based on a systemic and sociotechnical perspective; (2) New variables emerge from such analysis; and (3) It helps to understand better the elements needed for KT management in the NPD process.