The configuration consisting of a dielectric rod, surrounded by a plasma shell and a concentric outer conducting cylinder, is investigated theoretically and experimentally for its propagation characteristics. It is predicted from the theory that such a configuration will support propagation in a backward wave mode (oppositely directed phase and group velocities). These backward waves were observed in experiments using a configuration essentially identical to the above (the dielectric rod had an air space down the center used to insert a probing antenna), with the plasma provided by a cesium discharge. Agreement between these observations and calculations is excellent. A forward wave was also observed at low frequencies, and is attributed to the influence of the sheath at the plasma‐conductor interface. The observed dispersion curve for this forward wave is also in good agreement with that calculated using the expected sheath size of the cesium plasma‐metal interface.