Heterocyclic compounds are an important part of the synthetic medicinal chemistry. They offer a high degree of structural variety and have proven to be widely useful as therapeutic agents. Heterocyclic compounds play an important role in the biological processes. They are widespread as natural products. Heterocyclic compounds are widely found in nature categorically in plant alkaloids, nucleic acids, anthocyanins, and flavones. They are also present as in chlorophyll and hemoglobin. "dditionally, some proteins, hormones, and vitamins also contain aromatic heterocyclic system. Heterocycles have huge potential as the most promising molecules as lead structures for the design of new drugs. "bout one half of over million compounds recorded so far in chemical abstracts are heterocyclic. The proposed book chapter entitled, Recent Advances in the Biological Importance of Rhodanine Derivatives gives an outline of importance and applications of the various rhodanine derivatives in medicinal chemistry from to .