Abstract
This review deals with the utility of hydrazonoyl halides in synthesis of bioactive heterocylic compounds such as pyrazoles, triazoles and pyrimidines which showed wide range of biological activities. We discussed here the synthesis of heterocyclic ring system derived from hydrazonoyl halides and their significant biological properties as for example, antitumor, antimicrobial, analgesic, anti-inflammatory, anti-H1N1 and anti HCV activity.