The main purpose of this paper is to use the fuzzy analytic hierarchy process (FAHP) approach to evaluate the key environmental risk factors for pollution at international ports in Taiwan. Relying on the literature and experts’ opinions, a hierarchical structure with three risk aspects and thirteen risk factors is first constructed, and a FAHP model then proposed. Based on data from the AHP experts’ questionnaires, we use the FAHP approach to determine key environmental risk factors. Finally, the results show that: (1) Air pollution is the most important aspect of environmental pollution at international ports in Taiwan. (2) In order of relative importance, the top five key environmental risk factors for pollution at international ports in Taiwan are the oil leaks from ships, volatile organic compounds (VOCs), exhaust emissions from ships at berth, harmful coatings on ships' hulls, and ships' failure to use low-pollution fuel. Furthermore, some discussions are provided for port authority in Taiwan.