Metal halide perovskite (MHPs) solar cells represent a promising newcomer in the front of emerging photovoltaic technologies to address the dramatic energy crisis and climate change that we are facing. The exceptional properties of MHPs derive by their hybrid organic-inorganic nature, which also allows a low-cost and straightforward fabrication process. Solar cells containing MHPs as absorbing layer have already achieved a power conversion efficiency of about 25,7 %, close to the efficiency of silicon-based devices. Nevertheless, a major limitation is related to the poor stability of the material when exposed to operative conditions, namely temperature, light and moisture, which still prevents the uptake of this technology. Therefore, to further improve the performances of these devices, many surface processes have been applied to solar cells interfaces, most of which include a solution-based methodology ¹. The aim of these treatments is not only to improve the efficiency of solar cells in terms of carrier concentration and transport properties, but also to improve device stability under working conditions. Among the different surface treatments exploitable, the use of plasma represents a solvent-free and non-invasive promising strategy to boost MHP solar cells performances. Plasma-deposited coatings on perovskite, as fluorocarbon polymers, have shown to improve material resistance to humidity and photoluminescence properties². We have explored low-pressure plasma as innovative treatment applied to Metylammonium Lead Iodide perovskite surface. Different gases were tested, i.e. Ar,  N2, H2 and O2, and an interesting improvement of perovskite photoluminescence was observed for the Ar and H2 plasma treated films. The photovoltaic devices including perovskite layers treated with Ar plasma showed increased PCE compared to the untreated solar cell, thanks to an efficient removal of the superficial organic component, that was revealed through X-ray photelectron spectroscopy (XPS). Importantly, XPS also allowed to rationalize the differences observed between the different gases, results corroborated by theoretical calculation of interfaces. Starting from this study, new plasma surface treatments, plasma-assisted deposition and encapsulation processes will be object of study of future research, to achieve a more complete understanding of the interfacial defects and charge carrier dynamics and to further minimize performance losses and instability issues.