N,N'-Dimethylurea is primarily used as an intermediate in the synthesis of various pharmaceuticals, particularly in the production of caffeine and other methylated compounds. It is also employed in the manufacture of resins and plastics, where it acts as a cross-linking agent to enhance the durability and stability of the final products. In agriculture, it serves as a slow-release nitrogen fertilizer, providing a steady supply of nutrients to plants over time. Additionally, it is utilized in organic synthesis as a reagent for introducing dimethylamino groups into molecules, facilitating the creation of complex chemical structures.