An experimental and computational study of an increasingly used third-generation common-rail injection system with a piezo actuator has been carried out. A complete characterization of the different elements of the system, both geometrically and hydraulically, has been performed in order to describe its behaviour. The information obtained through the characterization has been used to create a one-dimensional model that has been implemented in the commercial software AMESim and extensively validated against experimental data. The results of the validation demonstrate the model ability to predict the injection rate of the injector with a high level of accuracy, therefore, constituting a powerful tool in order to carry out further studies of this type of injection system. ; Ministerio de Ciencia e Innovacio´n in the frame of the project ‘Estudio teo´rico experimental sobre la influencia del tipo de combustible en los procesos de atomizacio´n y evaporacio´n del chorro Diesel (PROFUEL)’ [grant number TRA 2011-26293] ; Salvador Rubio, FJ.; Plazas Torres, AH.; Gimeno García, J.; Carreres Talens, M. (2014). Complete modelling of a piezo actuator last-generation injector for diesel injection systems. International Journal of Engine Research. 15(1):3-19. doi:10.1177/1468087412455373. ; Senia ; 3 ; 19 ; 15 ; 1