Apparatus, methods, and computer-readable media for facilitating opportunistic CSI for sidelink communication are disclosed herein. An example method for wireless communication at a responding sidelink UE includes receiving, from an initiating sidelink UE, a request to provide CSI feedback to the initiating sidelink UE, the request excluding a CSI-RS. The example method also includes decoding a transmission from the initiating sidelink UE to a neighboring sidelink UE, the transmission including a CSI feedback trigger. The example method also includes transmitting, to the initiating sidelink UE, a CSI report based on the transmission.