Companies in the twenty-first century are exposed to a variety of pressures to respond to environmental issues, and responding to these pressures affects several aspects of business such as purchasing, marketing and logistics. Managers increasingly view sustainability as a complement to their corporate agendas, or even as an opportunity. It is important to understand how firms integrate environmental issues into their businesses and how these integration strategies affect performance. The process of sustainable new product development (SNPD) is a key strategic focus to achieve economic and environmental sustainability. This paper examines the integration of environmental specialists into new product development teams that are composed of other functional specialists including marketing, manufacturing, and R&D personnel, and its impact on SNPD project performance across three stages; concept development, product development, and product commercialization. We empirically test our theoretical model using a sample of 219 firms from a range of business-to-business industries. We present evidence that integrating an environmental specialist into a new product team has a positive influence on SNPD project performance beyond what the traditional members of such a team would accomplish. We analyze this relationship across the stages of SNPD to obtain a clearer picture of the effects of this integration. In particular, the integration of the environmental specialist was more effective on SNPD project performance in the final stage of the SNPD process when the product was being launched; this effect is even greater for high-innovative projects. Published by Elsevier Inc.