An embedded piezoelectric based Lead Zirconate Titanate (PZT) sensor is developed to monitor the early age progression of hydration and development of material stiffness of cementitious materials. The setting behavior of cement mortar is monitored continuously by analyzing the electromechanical (EM) responses of the embedded PZT sensor. The evolving mechanical impedance of the cementitious material is extracted from the measured coupled EM response of the sensor embedded inside mortars of different compositions. The changes in the EM conductance obtained from the embedded PZT sensor is shown to be sensitive to the composition of the mortar and the presence of admixtures which alter the rate of early hydration. The mechanical impedance of the mortar medium extracted from the EM measurement of the embedded sensor is shown to sensitively reflect the progressive change in the stiffness of the mortar material as it transforms from a fluid to a solid state. © 2017 SPIE.