After recalling the components and the factors influencing the pain, are stated the main reasons which needs for the evaluation of the pain. The different methods allowing an evaluation of the pain are then described with their advantages and disadvantages. These methods are based on, on one hand on questonary with as a support the use of different mono or multidimensional scales and on the other hand a clinical examination. The goal of this proceeding is to elaborate a scale of the pain for a better adaptation of it's therapy.