3,4-Dichloroiodobenzene is primarily used as an intermediate in organic synthesis, particularly in the production of pharmaceuticals and agrochemicals. Its structure allows for further functionalization, making it valuable in cross-coupling reactions, such as Suzuki or Sonogashira couplings, to create complex organic molecules. It is also employed in the development of liquid crystals and advanced materials due to its halogenated aromatic properties. Additionally, it serves as a precursor in the synthesis of compounds for research in medicinal chemistry and material science.