In this paper we employ a nonlinear acoustic method, namely, the vibro-acoustic modulation method, for the detection of delamination and kissing bond in composites. Both a (large-amplitude and low-frequency) pumping wave and a (low-amplitude ultrasound) probing wave are used to vibrate the structure. Permanently bonded piezoceramic transducers are used for both excitation and measurement. A side-band ratio is used to estimate the extent of nonlinear interactions between the two input waves in the structure. Current results show that the proposed method successfully differentiates the intact specimens from both the delamination and the kissing bond specimens used in this study.