This research examines the effects of purchasing and supplier involvement on new product success. Two hundred fifty-two senior purchasing managers completed a mail questionnaire that addressed a wide range of issues regarding the effects of purchasing and supplier involvement, the management of supplier involvement, the organization's strategic orientation, and the organization's competitive environment on new product success. The results indicate that the organization's strategic orientation and competitive environment, purchasing involvement, and supplier involvement affect new product success. The appropriate level, timing, and frequency of supplier involvement was found to vary with the situation. The results also provide insight into the role of purchasing in new product development and the effective management of supplier involvement in new product development.