A recent debate in the Nature magazine has again talk about the subject of the relevance of the Impact Factor. This article definesif this point is a valid measurement in the scientific evaluation. It exposes some of the problems that the IF faces and analyzes some of the problems derived from their use and manipulation. It concludes indicating that the IF does not have to be used like the only measurement in the evaluation of the scientific activity but that must be complemented with other indicators to mainly measure correctly the scientific activity in zones as Latin America.