This review includes detailed study of structures of various hydrazones synthesized and evaluated for their antimicrobial activity. Hydrazone is a class of organic compounds with structure R1R2C=NNH2. Hydrazones containing an azomethine -NHN=CH- proton which leads to an important class of compounds for new drug development. Hydrazones are present in many of the bioactive heterocyclic compounds that are of very important use because of their various biological and clinical applications. Therefore, many researchers have synthesized these compounds as target structures and evaluated their antimicrobial activities. These observations have been guiding for the development of new hydrazones that possess varied biological activities.