1-Ethyl-1-phenylhydrazine is primarily used in organic synthesis as a building block for the preparation of various heterocyclic compounds. It serves as a key intermediate in the synthesis of pharmaceuticals, particularly in the development of drugs targeting central nervous system disorders. Additionally, it is utilized in the production of agrochemicals, where it contributes to the creation of pesticides and herbicides. Its role in chemical research includes the study of hydrazine derivatives and their reactivity, aiding in the development of novel chemical entities. The compound is also explored in material science for the synthesis of specialized polymers and coatings with unique properties.