Abstract The time evolution of the electric signals emitted during uniaxial compression of prismatic cement mortar specimens is investigated in this study. The electric signals are recorded in the form of very weak electric currents, and their analysis is achieved in terms of the Pressure Stimulated Currents technique. The study is focused on the quantification of the role of the specimens’ age, i.e., the time interval between the production of the specimens and the implementation of the tests, on the intensity of these electric signals. In this context, four classes of specimens were tested, including specimens of ages equal to 3, 14, 28 and 90 days. It was concluded that for early ages the Pressure Stimulated Currents are quite stronger in comparison with those of mature specimens. There were no detectable differences between the specimens of ages 28 and 90 days, neither concerning the electric activity nor the mechanical response. Moreover, it was indicated that during loading, the electric activity is strongly intensified only after the mechanical response of the specimens abandons linearity, independently of the specimens’ age. Finally, it was concluded that the time evolution of the electric activity provides indicators that can be considered as pre-failure warnings, i.e., signals of upcoming fracture.