Integrated product development (IPD) is an approach for developing new products focused on the early and active involvement of design, manufacturing, marketing and other key new product development (NPD) stakeholders in order to achieve cross-functional integration and concurrent execution of various NPD activities. The benefits of IPD are well known in both the academic literature and popular press, including significant reductions in NPD cycle time and costs. However, in spite of these benefits, for the majority of manufacturing organizations, IPD is not used on 100% of NPD projects. This research develops a model of the organizational contextual factors influencing the diffusion of IPD in organizations. Results of surveying 269 NPD managers indicate that the complexity of certain IPD practices and support for IPD directly influence IPD diffusion, while an innovative organizational climate and the complexity of the organization's NPD activities indirectly influence IPD diffusion through IPD support.