Provided are: a nonaqueous electrolyte secondary battery which comprises a flattened wound electrode body and has high capacity, good charge/discharge cycle characteristics and good productivity; and a positive electrode which enables the configuration of this nonaqueous electrolyte secondary battery. A positive electrode for nonaqueous electrolyte secondary batteries, which is used for a nonaqueous electrolyte secondary battery that has a wound electrode body obtained by winding a laminate of a positive electrode, a negative electrode and a separator into a coil shape and flattening the wound electrode body to have a flattened cross-section and that has an upper limit for charging voltage set to 4.3 V or more, and which comprises a collector that is formed of a metal and positive electrode mixture layers that are formed on both surfaces of the collector and contain a positive electrode active material, a conductive assistant and a binder. The collector has a thickness of 11 μm or less and a tensile strength of 2.5 N/mm or more. The positive electrode mixture layers contain, as the binder, a vinylidene fluoride-chlorotrifluoroethylene copolymer. A nonaqueous electrolyte secondary battery which is provided with a nonaqueous electrolyte and a flattened wound electrode body having the above-described positive electrode, and which has an upper limit for charging voltage set to 4.3 V or more.