In this work, we showed how cellular polypropylene (PP) films of controlled morphologies and good piezoelectric properties were developed by using twin-screw extrusion/calendaring. It was observed that the use of supercritical nitrogen (N2) as a physical blowing agent led to thin cellular PP films of around 500 microns with a controlled cellular morphology. In addition, the use of calcium carbonate (CaCO3) as nucleating agent substantially improved the cell size and cell density of the developed cellular films. The optimization of the extrusion parameters, such as screw configuration and temperature profile, as well as post-extrusion conditions such as calendaring temperature and rotational speed, led to a stretched eye-like cellular shape of uniform cell-size distribution. This particular morphology led to higher storage and loss moduli in the extrusion/calendaring (longitudinal) direction than for the transverse direction. Particularly, higher cell aspect ratio led to lower Young�'s modulus and consequently a higher quasi-static piezoelectric d33 coefficient of around 550 pC/N. In addition, we used the dynamic mechanical analysis (DMA) as a simple and rapid technique to predict the piezoelectric behavior of the cellular films. In this method, two new parameters that we called anisotropic moduli ratios (AMR1 and AMR2) were proposed to quantify the film cellular structure. They respectively correspond to the ratio of the storage and loss moduli in the longitudinal (L) direction over those in the transverse (T) direction (AMR1 = E�Œ(L)/E�Œ(T) and AMR2 = E��(L)/E��(T)). The results showed that film samples with more elongated eye-like cells (higher cell aspect ratios) had higher AMR1 and AMR2 values. The variation of the d33 coefficient with respect to AMR1 and AMR2 was also studied and the corresponding results showed that d33 increases with increasing both AMR1 and AMR2.