In this paper, two procedures for damage detection in Carbon Fiber-Reinforced Polymer (CFRP) plates are shown. One is based on the use of statistical frequency series to detect the presence of damage. This method was tested experimentally on a CFRP plate with induced damage. The other one is a procedure based on Ritz method and wavelet transform that was applied to the numerical vibration modes of a damaged CFRP plate. The former method can also be used experimentally, even if the material engineering constants are unknown.