This paper develops an efficiency-based approach for evaluating the performance of available electronic markets (e-markets) in the active pursuit of sustainable electronic business through the selection of specific e-markets for small and medium-sized enterprises (SMEs). An efficiency-oriented evaluation model using data envelopment analysis is developed first for identifying efficient e-markets. A multicriteria decision making model is then proposed for solving the e-markets selection problem with respect to the specific characteristics of e-markets and the unique nature of SMEs in specific situations. Such a model can adequately consider the imprecision and uncertainty in the decision-making process using linguistic variables approximated by fuzzy numbers to express the subjective assessments of the decision maker when evaluating the overall performance of individual e-markets. As a result, the most appropriate e-market in a specific situation for individual SMEs can be selected for the development of a sustainable electronic business. A real-life example is given for demonstrating the effectiveness of the proposed approach for addressing the e-market selection problem in the real world.