Guided acoustic waves along interfaces and more complex layered structures are often used in ultrasonic NDE. Their outstanding sensitivity to specific properties associated with interface conditions and bond quality is due to the fact that their energy is effectively confined to the region of interest. On the other hand, this advantage turns out to be a great drawback for generation and detection of such guided waves. Certain modes with higher phase velocity than at least one of the bulk velocities of the surrounding media are called leaky modes that can be coupled to via phase matching bulk waves. True guided modes of lower phase velocity than any of the bulk velocities of the surrounding media are much more difficult to generate and detect. A simple experimental technique based on longitudinal or shear wave excitation along the interface is shown to be very effective in generating both symmetric and antisymmetric guided modes of Rayleigh (SV) or Love (SH) type of polarization. Experimental results from different plates and adhesive and solid-state interfaces are shown to be in good quantitative agreement with theoretical calculations. This technique might find numerous applications in basic acoustic studies as well as ultrasonic nondestructive evaluation. [This work was supported by the Office of Naval Research under Contract N0014-C-2129.]