Inorganic perovskite-type oxides are fascinating nanomaterials for wide applications in catalysis, fuel cells, and electrochemical sensing. Perovskites prepared in the nanoscale have recently received extensive attention due to their catalytic nature when used as electrode modifiers. The catalytic activity of these oxides is higher than that of many transition metals compounds and even some precious metal oxides. They exhibit attractive physical and chemical characteristics such as electronic conductivity, electrically active structure, the oxide ions mobility through the crystal lattice, variations on the content of the oxygen, thermal and chemical stability, and supermagnetic, photocatalytic, thermoelectric, and dielectric properties.Nanoperovskites have been utilized as catalysts in oxygen reduction and hydrogen evolution reactions exhibiting high electrocatalytic activity, lower activation energy, and high electron transfer kinetics. In addition, some perovskites are promising candidates for the development of effective anodic catalysts for direct fuel cells showing high catalytic performance. Moreover, they are recently utilized in electrochemical sensing of alcohols, gases, glucose, H 2 O 2 , and neurotransmitters. They can enhance the catalytic performance in terms of selectivity, sensitivity, unique long-term stability, excellent reproducibility, and anti-interference ability. In addition, organometallic halide perovskites exhibited efficient intrinsic properties for photovoltaic solar cells exhibiting good stability and high efficiency.This chapter introduces a comprehensive coverage of the progress in perovskites research and their applications. Emphasis is given toward several intrinsic properties of perovskites, namely, electronic conductivity, electrically active structure, and electrochemical performance in terms of synthesis routes and stability. The different synthesis methods of the perovskites (coprecipitation, sol-gel, microwave, citrate/ nitrate, etc.) will be summarized in this chapter. The synthesis method affected
