high defect tolerance, long carrier diffusion length, and compatibility toward scalable manufacturing processes to name a few. [2][3][4][5][6][7] However, hybrid perovskites face severe degradation issues under operative conditions, which stem from the (photo) chemical instability when exposed to moisture, oxygen, UV light, and heat. [8][9][10][11][12] Among other reasons, the presence of the hydrophobic organic cation, e.g., methylammonium, can accelerate the degradation path. [12][13][14] For this reason, a greater focus has been devoted to exploring inorganic elements to replace the organic cations, for instance, using cesium to form CsPbX 3 all-inorganic perovskites. This system has been revealed of particular interest especially for the improved thermal stability of the material and, consequently, the enhanced device lifetime. [13] CsPbI 3 and CsPbBr 3 are the most studied materials within this class, with a rapid boost of their use for highly efficient solar cells, reaching 19.03% in 2019. [15] However, the PCE of CsPbX 3 -based devices are still lower than their organic-inorganic counterparts and far from the Shockley-Queisser limit calculated for their bandgap. [16] Therefore, major efforts are required to stabilize the CsPbI 3 structure and to fabricate high quality CsPbX 3 thin films, before upscaling the manufacturing toward marketable devices. In this work, we provide a compelling perspective on the most recent and innovative strategies to tackle this challenge. The structural and optoelectronic properties of CsPbX 3 materials are first sorted out, with a focus on the film morphology, crystal structure, and phase transitions of each system. Second, methods for improving the photovoltaic performances and the stability of CsPbX 3 -based devices are reported, focusing on the highest PCE and the longest device lifetimes reported up to date. Finally, we provide a perspective on the state of the art and future challenges for the upscaling of all-inorganic perovskite modules.