Energy-dispersive X-ray analysis (EDS) coupled to a scanning electron microscopy (SEM) could represent a valuable tool in the study of solid dosage forms. In particular, EDS can be useful in the control of conventional pharmaceutical formulations by determining the presence and the distribution of characteristic compounds. More recently, the growth in the development of modified release dosage forms needed the determinations of parameters affecting the drug delivery. Among these, drug distribution, elements involved in crosslinking procedures and coatings of "reservoir" systems could easily and rapidly evaluated by EDS analysis. In this paper, we report the theoretical aspects and some applications of the EDS technique especially concerning controlled release dosage forms in order to show the versatility of such an analytical method which could be widely used in the future.