The sluggish kinetics of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) have been one of the bottlenecks hindering the commercial application of rechargeable metal-air batteries. This report describes the viability of synthesis of self-supported Au-based alloy (AuCuCo) by a facile one-pot hydrothermal method and their use as highly efficient catalysts for ORR and OER. The obtained AuCuCo exhibits comparable electrocatalytic activity and better stability toward both the ORR and OER in alkaline media as compared with commercial Pt/C and IrO2/C catalyst. The improved electrocatalytic activity of AuCuCo is attributed to its unique three-dimensional nanostructure, the abundance of twin crystals, and change in the electronic structure of Au by alloying.