Lithium–oxygen (Li–O₂) batteries are receiving intense interest because of their high energy density. A new tubular δ-MnO₂ material prepared by a simple hydrothermal synthesis is an efficient electrocatalyst for Li–O₂ batteries. The synthesized δ-MnO₂ exhibits a unique tubular structure, in which the porous walls are composed of highly dispersed ultrathin δ-MnO₂ nanosheets. Such a unique structure and its intrinsic catalytic activity provide the right electrocatalyst characteristics for high-performance Li–O₂ batteries. As a consequence, suppressed overpotentials—especially the oxygen evolution reaction overpotential—superior rate capability, and desirable cycle life are achieved with these submicron δ-MnO₂ tubes as the electrocatalyst. Remarkably, the discharge product Li₂O₂ of the Li–O₂ battery exhibits a uniform nanosheet-like morphology, which indicates the critical role of the δ-MnO₂ in the electrochemical process, and a mechanism is proposed to analyze the catalysis of δ-MnO₂.