Surface-acoustic-wave (SAW) devices incorporating conducting Langmuir-Blodgett (LB) films are reported for the first time. Excellent characteristics have been obtained using a mixed valence charge tranfer salt of a substituted pyridinium tetracyanoquinodimethane. The control afforded by the deposition technique has enabled the fractional change in surface wave velocity due to the electrical effects to be distinguished from those due to mass loading. The resistivity of the organic surface layer is measured to be 2Ωcm.