We deal with the problem of automatic visualizing large set of medical data and propose a framework that addresses the involved issues. Our approach does not depend on the particular data under analysis and its aim is to produce a highly effective visual representation. Such objective is made possible by the consistency of a set of logic rules contained in a knowledge base. These rules express facts and relationships about the visual domain, the data domain, the mapping between both domains, and the perceptual domain. Our approach has been tested against a challenging set of data, i.e., the biomedical data coming from the Nefrology Center of the Civil hospital of Vigevano.