In this study lead zirconate titanate (PZT) transducers are employed for damage detection of six reinforced concrete elements (four beams and two columns) retrofitted with carbon fiber reinforced polymer (CFRP) jackets. The PZT transducers were placed externally on the CFRP jackets in an effort to detect the damage underneath the jackets. Measurements of the voltage across the PZT transducers were obtained at various strain values during the experimental procedure. The transducers were placed in positions where the failure of the CFRP jackets was expected to be more intense. The variation of the voltage as the strain increases is the indication of damage. The damage index employed for the quantification of the damage is the root-mean-square-deviation (RMSD) index. The experimental results lead to the conclusion that the measurement system employed in combination with the PZT transducers provide safe evidence that damage detection can be achieved at an early stage.