New strategies are necessary against the increased complexity of making quick and cohesive decisions. The deficiency in knowledge organization and information may refer the organization to great problems with regard to the process of decision making. The aim of this paper was propose a model of support for decision making based on knowledge management that can assist managers in this deciding task. This study is based on the model proposed by Dalfovo (2007) that integrates knowledge management and competitive intelligence. It's is based on three assumptions: (1) tacit knowledge, formed by experience, informal skills, values and principles are used by managers as a parameter in decision making; (2) organizations do not use knowledge and information they have to assist in decision making because they are not properly filtered and organized; (3) decision support systems facilitate the knowledge and information use and promote the transformation of tacit and explicit knowledge. The study had as audience, the managers from Catarinense Federal Institute, which have responsibility level of strategy. It was adopted a quantitative descriptive methodological design, which aimed to analyze the frequency and relationship of the quantitative data obtained through a questionnaire with a Likert scale of five points. The main results showed that the tacit knowledge has great influence in decision making. The assumptions were confirmed and were suggested six propositions, which serve as inputs to implement a decision making model based on knowledge management.