This paper is aimed at the risk assessment of operational safety for oil tankers. Based on the operational features of oil tankers and relevant literature, the Risk Factors (RFs) of operational safety were first identified. A revised risk matrix based on a fuzzy Analytical Hierarchy Process (AHP) approach was then proposed to assess the risk classes of the RFs. Finally, to validate the research model, the oil tanker fleet of Chinese Petroleum Corporation (CPC) in Taiwan was empirically investigated. The results can provide practical information for oil carriers to improve their ships' operational safety. Furthermore, the revised risk matrix may provide a theoretical reference for methodological researches in safety risk assessments.