In this study, nonlinear optical (NLO) properties of CsPb(Cl/Br)3 perovskite quantum dots (PQDs) and Zn doped CsPb(Cl/Br)3 PQDs was systematically investigated, discovering its potential for advanced NLO devices. Initially samples were synthesized and characterised using UV-Vis, photoluminescence (PL), and TEM method. Next, open and closed aperture Z-scan experiments and optical limiting evaluations were carried out under varying excitation conditions. We measured that nonlinear absorption (β), nonlinear refractive (n2) indices and third-order nonlinear susceptibility (χ3) for CsPb(Cl/Br)3 PQDs to be on the orders of 10−11 cm/W, 10−16 cm2/W and 10−14 esu, respectively. Interestingly, it has been observed that the NLO properties of Zn -doped samples beings prominent considerably compared to undoped samples, with the rate of increasing as the Zn content. The results show that CsPb(Cl/Br)3 PQDs are remarkable material for applications on the next-generation NLO devices.