[en] Full text: Particle size distribution is one important parameter in powder fabrication developments; it has been decided to use a method complementary to sedimentation method. Thus, the optical method was chosen for that purpose, since it can give additional information, such as identification of geometrical parameters in particles without spherical symmetry and account for those particles, with diameters above 100 microns, that sediment before the run starts. On the other hand, through the use of electronic microscopes it is possible to observe particle sizes lower than 0.1 micron, which is the limit of the sedimentation techniques. It is also possible not to depend on the arbitrary selection of particle density, which is difficult to estimate in the case of compounds with internal porosity. To make this method operative, and to use it normally, it is necessary to have an automatic system of image analysis, which allows to separate the particles for its counting and qualification. Therefore, it is necessary that the particles could be seen in screen separately, individually, without superposing. As in the sedimentation techniques, it is necessary to find the conditions to disperse the particles, in such a way that they can set individually in the slide. In this work, the necessary steps to reach the optical measurement and the method used to perform it, are explained. Distributions of calibrated populations, perfect spheres and particles of varied and irregular morphologies, performed by both methods, are compared, and the correspondence and application range of both is intended to find. Distributions with different number of particles are analyzed, in order to determine the necessary minimum quantity of particles to enable a regular distribution. Also, how dependent is the population considered on the sample diameters dispersion and the number of images at different increases, necessary to cover the selected population