Whenever relationships among variables are complex, or time processes play an essential part, or random components mask the process under study, graphical display becomes an indispensable tool. Biomedicine, in a broad sense, from research to medical care or management activities, is a field with these features, and good use of graphics can facilitate a new and valuable approximation to the available information. The aim of the paper is twofold: to explain to the reader that graphical display is not limited to be some way to attract information quickly, but means and instrument in the process of knowledge acquisition, and to stress that graphical language needs some maturity, and perhaps some guidelines, so that quantitative information will be revealed through high-quality graphics, avoiding worthless and mechanical displays.