The self-assembly of Ge1Sb2Te4 nanowires (NWs) for phase change memories application was achieved by metal organic chemical vapor deposition, catalyzed by Au nanoislands in a narrow range of temperatures and deposition pressures. In the optimized conditions of 400 °C, 50 mbar, the NWs are Ge1Sb2Te4 single hexagonal crystals. Phase change memory switching was reversibly induced by nanosecond current pulses through metal-contacted NWs with threshold voltage of about 1.35 V.