The infrared audit is a technique of investigation that allows one to obtain, in an indirect way, a thermal mapping of a surface. Applications of thermography in the energy fields are very widespread, since through such an investigation, which is non-invasive, and a correct interpretation of infrared images, it is possible to highlight inefficiencies on buildings and facilities. This chapter describes the application of infrared audits in support of energy audits. The potential of this technique, but also its critical aspects due essentially to errors during the shooting and mistakes in thermogram interpretation will be discussed. © Springer-Verlag London 2013.