The invention provides a piezoelectric polymer film. The piezoelectric polymer film contains a helical chiral polymer (A) having a weight average molecular weight of 50,000 to 1,000,000 and having optical activity, has a degree of crystallinity of 20% to 80% as measured by a DSC method, and has a standardized molecular orientation ratio MORc of 3.5 to 15.0 as measured with a microwave transmission-type molecular orientation meter employing a reference thickness of 50 mu m. When phase difference streaks in the film are assessed by an assessment method A in which the direction that is parallel to the phase difference streaks is defined as direction X and the direction that is orthogonal to the direction X and is parallel to the main surface of the film is defined as direction Y, the number of phase difference streaks each having an assessment value of 60 or more is 0 and the sum total of assessment values of phase difference streaks each having an assessment value of 20 or more is 1000 or less per a length of 1000 mm as observed in the direction Y.