Traditionally, companies have considered factors such as price, quality, flexibility, etc. when evaluating supplier performance. Meanwhile, many of them have also begun to consider "green" issues with the increasing environmental pressures. This paper presents an evaluation model based on a specific multi-criteria decision-making method, namely VIKOR, for rating suppliers' environmental performance. The original VIKOR method has been proposed to identify compromise solutions, by providing a maximum group utility for the majority and a minimum of an individual regret for the opponent. In its original setting, the method treats exact values for the assessment of the alternatives, which can be quite restrictive with unquantifiable criteria. This will be true especially if the evaluation is made by means of linguistic terms. For this reason, we extend the original VIKOR method so as to process such data and to provide a more comprehensive evaluation in a fuzzy environment. The enhanced method is demonstrated with an industrial case.