The concept of intelligent material/structure, largely debated for a few years, is generally applied to systems able to react to internal stimuli (selfcontrol) and external ones (adaptation to environmental conditions) in order to realize in the best way the function for which they have been designed. These systems include, in the most general case, sensors, actuators, bonded to the surface or integrated in the bulk of the structure, and a control unit. ONERA (Office National d'Etudes et de Recherches Aerospatiales), as other research institutes for aeronautics and aerospace, has undertaken for years important studies on intelligent vibration control of structures, at the Structures Department. More recently, at the Physics Department, we started investigations on the smart non destructive evaluation of composite aeronautical structures, typical materials being laminates carbon/epoxy, a few millimeters thick. As the sensors we intend to use are either optical fibers or piezoelectric ceramics, we have had to study their integration in the material. If the incorporation of optical fibers has been the object of numerous investigations, on the contrary, the integration of piezoelectric elements has been rarely tackled. The objective of this paper is to present the study we have started in this field, which we consider to be a critical one, and on which depends the future development of intelligent/smart structures. After a short bibliography, we give first a brief description of the integration of optical fibers, carried out at our laboratory and, second, a more detailed study of the embedment of piezoelectric elements in a stratified composite, including a technological part and a theoretical part.