Aniline hydroiodide is primarily used in organic synthesis as a reagent for the preparation of various iodine-containing compounds. It plays a significant role in the synthesis of pharmaceuticals, particularly in the development of iodine-based drugs. The compound is also utilized in the production of dyes and pigments, where it acts as an intermediate in the formation of complex colorants. Additionally, aniline hydroiodide is employed in research laboratories for studying chemical reactions involving iodine and aromatic amines. Its ability to release iodine under specific conditions makes it valuable in certain catalytic processes and in the modification of organic molecules.