Today “ecodesign” is a necessary consideration in the product development process. With increasing general awareness of the need for environmental production and more stringent regulatory requirements, manufacturers have to try to minimize their environmental impact. Life-cycle assessment (LCA) methodology is a generally accepted quantitative approach that can be applied to support environmental impact evaluations of a product. However, despite the time-consuming and resource-consuming attributes of the LCA, it has difficulty to deal with uncertain information. Therefore, LCA is yet to be a practical approach for environmental impact evaluation, particularly, during new product development (NPD). This paper proposes an approach to evaluate the environmental performance of design alternatives during NPD. The use of multiple criteria decision-making (MCDM) approaches with LCA methodology for the evaluation of design alternatives’ environmental performance during NPD processes is first discussed. The proposed approach integrates analytic hierarchy process (AHP) and fuzzy set theory (FST) with evidential reasoning (ER) in the evaluation of environmental performance to prioritize different design options. A case study is described to illustrate the use of the proposed method.