Certain aspects of the present disclosure provide techniques for beam refinement reference signal (BRRS) design for millimeter wave (mmWave) system in shared spectrum. The techniques can include a method for wireless communication that includes transmitting at least one of a request-to-send (RTS) or a clear-to-send (CTS) within a frame using frequency resources in a shared spectrum, and including a beam refinement reference signal (BRRS) in the at least one of the RTS or CTS.