Display omitted •Grain boundary defect passivation.•Points defects neutralisation.•Environmental stability.•Surface defects neutralisation.•Passivation of transporting layer. Organo-metallic perovskite solar cells emerge as a disruptive technology having the potential to revolutionise solar photovoltaic harvesting industries and become one of the most efficient and low-cost technologies due to their fabrication methods and flexible designs. However, the light-harvesting capabilities of these devices are still limited by excessive non-radiative recombination arising from the surface/volume defects which inhibit its industrial applications. Therefore, the process of elimination of these defects commonly known as passivation is very much essential. This review illustrates and summarizes categorically these defects and their origins and demonstrates different passivation techniques that have been adopted recently to improve the efficiency and stability of hybrid perovskite materials toward its potential solar cell applications.