Abstract . For immense demand of speedy high-end gadgets, chips are becoming denser, but Moore's law is falling flat lately. Complementary Metal-Oxide-Semiconductor (CMOS) technology is on its brink. Quantum-dot cellular automata (QCA) has become a potential alternative technology to provide faster speed with low power dissipation at nano-scale extent. Here, we proposed an efficient QCA design of 1-bit comparator. The proposed comparator required 59% less area and dissipated 82% less energy. QCADesigner has been used to design and simulate the proposed comparator. Finally, QCAPro tool has been employed for estimating energy dissipation. Keywords: Comparator, Energy dissipation, QCA Designer, QCAPro