Wi-Fi transmission can consume much energy even when it has no data packet to receive or transmit. Standard power saving mode (PSM) has been used to save energy but under PSM a station cannot achieve satisfactory performance when traffic pattern changes frequently. Now that more and more mobile devices have been equipped with multiple wireless interfaces, such as Wi-Fi, Bluetooth and ZigBee, we proposed and implemented a ZigBee-assisted power saving management (ZPSM) scheme, which wakes up Wi-Fi interface on-demand to increase energy efficiency and reduce delay time. Experiments have shown that ZPSM can achieve both energy efficiency and low packet delivery delay for stations, and the scheme is feasible to implement in resource constrained mobile devices.