The invention concerns a method and system of locating objects by means of UWB signals, the system including a search device (D1), incorporated in a portable apparatus (11) and provided with a pair of antennae (A1, A2), and at least one target device (D2) attached to an object sought (12). The target device (D2) includes, in addition to the transceiver (34, 35), a very low power consumption wake up receiver (46) which, when the target device is in a standby state, can receive a UWB wake up signal to switch on said device. This target device is arranged for measuring a time difference (tdiff) between the respective receptions of two locating signals respectively emitted by the two antennae (A1, A2) of the search device and for transmitting said time difference in a return signal that further contains, in a preferred variant, a signal processing time (trproc). Thus, it is not necessary for the two devices to be synchronized. Preferably, the search device (D1) is incorporated in a wristwatch (11) the two hands (51, 52) of which are used for indicating the direction or possible directions of the object sought (12).