In this work, Zinc Oxide based Piezoelectric Nanogenerator (PENG) over the flexible Kapton Polyimide (PI) substrate has been developed. The device performance has been improved by laser texturing of PI substrate which has increased the effective surface area of PI and adhesivity of ZnO thin film with PI substrate to improve the reliability and lifespan of the device. The untextured PI based PENG has generated a peak‐to‐peak output voltage, current, and power of 6 V, 420 nA, 2.42 μW, respectively, which has increased to 15.8 V, 790 nA, and 12.51 μW, respectively, on using textured PI obtained by 60% laser spot overlap. On further increasing the laser spot overlap to 80%, the peak‐to‐peak output voltage, current, and power have improved to 22.2 V, 1210 nA, and 26.88 μW, respectively. Therefore, as compared to the untextured polyimide‐based PENG, laser textured polyimide based PENG is a promising candidate for energy harvesting applications.This article is protected by copyright. All rights reserved.