Gases such as hydrogen and methane are conventionally stored using either compression or liquefaction. However, both approaches have limitations, which include the sophisticated hardware required for containment and the energetic cost of compressing or liquefying the gas. A potentially more efficient alternative is to use adsorption in highly porous materials, such as metal–organic frameworks (MOFs). To assess such adsorbents for gas storage applications, it is necessary to determine their gas adsorption properties as a function of temperature and pressure. The most common methods used for this purpose are the manometric and gravimetric techniques. This chapter begins by considering the applications for hydrogen, methane (natural gas), and carbon dioxide storage. It then discusses materials requirements, before covering H2, CH4, and CO2 adsorption by different MOFs. Manometric and gravimetric gas sorption measurements are then described and experimental considerations for performing accurate measurements are discussed in some detail. The chapter concludes with a discussion of future research trends.