Techniques are provide for passive positioning of user equipment (UE) with sidelink assistance. An example method for passive positioning includes receiving a first positioning reference signal from a first station at a first time, receiving a second positioning reference signal from a second station at a second time, receiving positioning assistance data associated with positioning reference signals received by a proximate user equipment, determining a reference signal timing difference based at least in part on the first time and the second time, and determining a current location based at least in part on the reference signal timing difference and the positioning assistance data.