In this work we present how 3-dimensional ferroelectric domains observed in MAPbIs affect the performance of perovskite solar cells. We simulated a 3D system with dimensions of 500 nm × 500 nm × 300 nm, considering domains with 100 nm side length which have been assigned random orientations of the polarization field. Calculations are performed with the simulator TiberCAD using a 3D drift-diffusion model, that simulates the light absorption and charge carrier transport, including the local polarization. We show that the presence of polarization domains have a strong impact on the charge carrier separation, leading to a reduction of electron-hole recombination and current pathways formation at interfaces.