Multicriteria analysis can be incorporated as a method to model preferences and facilitate decision making within a group of decision makers. In this paper we present a Group Decision Support System model, which utilizes multicriteria analysis to support decisions in a collaborative team. In brief, the model is based on the synthesis of group members’ preferences following an appropriate aggregation procedure. The resulting group preference is used as input for the relevant multicriteria methodology to produce the decision outcome. In this paper we present a variation focusing on classification decisions in group setting. We outline the overall methodology as well as the architecture of a prototype group decision support system and present an application in a financial classification problem.