The main objective of Sulfur Recovery Units (SRU) is to remove sulfur compounds (mainly hydrogen sulfide) from gases produced by sweetening of refinery or sour field production gases. The sulfur compounds are converted to elemental sulfur, and then the sulfur is condensed to liquid sulfur. The feed contains mainly hydrogen sulfides coming from amine and sour water units. Corrosion is a major concern in SRUs due to the presence of a high percentage of hydrogen sulfide as well as high temperatures in most of the unit’s equipment. This paper will demonstrate the fundamental corrosion issues encountered in SRUs. In addition, it will address the Claus process’ chronic corrosion problems experienced in Saudi Aramco facilities, proposed protective actions and applicable corrosion monitoring techniques.