Commercialization of perovskite solar technology depends on reaching a stable functioning of the devices. In this regard, both intrinsic (chemistry phenomena of the different device layers) and extrinsic factors (environmental) need to be considered. In this chapter, we report the state of the art of encapsulation techniques against extrinsic degradation mechanisms. Our analysis includes the most common encapsulation structures, materials employed and their by-products, standard methods to test the stability of the devices (accelerated testing, outdoor and degradation monitoring), and security requirements to prevent the health/environmental hazard of lead leakage.