The relaxation and piezoelectric properties of polyvinylidene fluoride (PVDF) films modified by irradiation with heavy ions of Ne, Xe and Bi and subjected to chemical etching are investigated. It has been established that irradiation with ions of different masses leads to a change in the intensity and temperature position of relaxation peaks, which indicates the effect of ion exposure on the segmental mobility of macromolecules. After chemical etching, an additional relaxation process was detected in the region of about -10 ^oC, associated with the formation of a new type of relaxers. It is shown that the effect of a beam of heavy ions causes the appearance of a piezoelectric response, the magnitude of which increases with increasing charge and fluence of the incoming ions. Additional polarization in the negative corona discharge field enhances the piezoelectric response, while chemical etching leads to a decrease in the values of the d₃₃ modulus. The results obtained demonstrate a significant effect of the parameters of ion irradiation and subsequent chemical treatment on the relaxation and functional properties of PVDF films. Keywords: polyvinylidene fluoride, track membranes, ion irradiation, chemical etching, thermally stimulated depolarization current, piezoelectric module.