Anions and neutral molecules are biologically important chemical species, and they have a wide range of applications in industrial, agricultural and pharmaceutical sectors. Exposure to certain anions and neutral species at levels above permissible limits results in environmental pollution and adverse effects on living organisms. Their practical, accurate, sensitive and, where possible, in situ detection necessitates the use of analytical tools such as chemosensors that are easy to design and operationally practical. Heteroatomic chemosensors are widely used because they can interact with anions and neutral compounds with high selectivity using different bonding modes. This review discusses the application of hydrazone-based chemosensors for the determination and identification of anions an...