Partner selection is gradually recognized as an essential factor in gaining success in a cooperative settings. In this paper, a novel approach based on fuzzy AHP group decision-making for partner selection of joint venture projects is proposed. In this approach, rst, the in uential factors for selection of appropriate partners based on literature review and interviews with experts are identi ed. Then, using a method considering the risk, knowledge, and educational background of decision-makers, the impact of decision-makers is calculated. Pairwise comparison matrices are performed, and the weights of criteria are calculated based on two methods (multiplicative and additive). Then, the calculated weights of criteria and the potential partners have been ranked via an e cient ranking index. Finally, the application of this methodology to a real case study in National Iranian Petrochemical Company (NPC) is conducted. The contribution of this study is developing a fresh systematic approach for partner selection of international joint ventures and application in a real-life case study to present an operational guideline to the petrochemical industries. The results of this study reveal that the equipment of the partner, its nancial capacity, trusts and management skills are the most important criteria for establishing the durable partners in the international joint venture of NPC.