Provided is a biaxially stretched polypropylene film for capacitors having a thin thickness and having excellent initial voltage resistance and excellent long-term heat resistance and voltage resistance, and also provided is a metallized polypropylene film for capacitors. The polypropylene film for capacitors is obtained by biaxially stretching a polypropylene resin, the polypropylene film having a crystallite size of 122 Å or less as determined by the Scherrer's equation from the half width of the reflection peak from (040) plane of α-crystal measured by a wide angle X-ray diffraction method, and the polypropylene film having a value of birefringence ΔNyz with respect to a thickness direction of 7.0×10−3 or more and 10.0×10−3 or less as measured by an optical birefringence measurement.