The purpose of this paper is to evaluate the sustainable efficiency of container terminals (CTs). By the definition of United Nations Conference on Trade and Development (UNCTAD), business sustainable development includes three domains: Economics, Environment, and Society. Accordingly, based on the definition and the practical features of CT operations, this paper assesses sustainable efficiency for CTs from three perspectives: container throughput, CO2 emissions, and occupational safety. In this paper, a modality movement and a fuzzy grey relational analysis (GRA) approach are first proposed to estimate CO2 emissions and occupational safety index for CT operators, respectively. A hybrid slacks‐based measure (SBM)‐DEA model is then developed to assess the sustainable efficiency of CT operators. Finally, the CT operators in the Port of Kaohsiung are empirically investigated to validate the research model. Based on the results, theoretical and practical implications for the management of CT operators and port authorities are discussed.