The demand for improvement in the quality and cost control in health care stimulates the utilization of the Multiple Criteria Decision Making (MCDM) approach, which is a sub-discipline of operations research that explicitly evaluates multiple conflicting criteria in decision making. The aim of this paper was to develop a user-friendly multiple criteria decision making support system in order to facilitate the application of an MCDM method by decision-makers. The system was developed in Java and compares alternatives (i.e., technologies or projects) by a single or a group of individuals with a set of criteria evaluated by means of an ordinal or numeric scale. An ordinal scale is used to set the weights for each criterion. Then an MCDM method, known as TODIM (Tomada de Decisao Interativa Multicriterio, in Portuguese), aggregates the values attributed to each alternative for each criterion in order to obtain a ranking of the alternatives for each individual. Finally, some fuzzy aggregation methods are applied in order to reach a group decision. The preferences of eleven decision-makers, members of a graduate course in Health Technology Assessment at Rio de Janeiro, based on seven criteria, was obtained for three oncological medicine alternatives. Besides allowing the decision-makers to set the scenario of the priority setting process (specification of alternatives, criteria, evaluators and criteria scales), the system shows all the intermediate steps of the decision process, and how individual preferences are formed. Through its output, it is possible to identify patterns in the individual preferences, the most influential criteria, and to perform a sensitivity analysis in order to show how the outcome is sensitive to changes in the alternatives' evaluations. In this way the system brings transparency to the decision making process.