For mmWave directional air interface expected in 5G communications, the existing paging broadcast mechanism would be overwhelming. Transmitting the same paging information through multiple transmitting beams is essential since one transmission beam can provide only limited coverage. Thus, directional paging in high frequency 5G communications would substantially increase downlink resource overheads of the network. In this letter, we propose novel mobile assisted directional paging (MADP) as an effective solution to reduce paging overheads in directional communications. Numerical analysis of MADP achieves over 40% gain in network resource reduction compared to directional paging without mobile assistance. Our analysis is validated against simulations on real traffic trace.