Isatin is an important class of heterocyclic compounds. Recently, heterocyclic compounds analogues and their derivatives have attracted strong interest in medicinal chemistry due to their biological and pharmacological properties. The small and simple isatin nucleus possesses numerous biological properties like -antitumor, antimicrobial, anti-inflammatory, anticonvulsant, antiviral, anti HIV, antioxidant, CNS depressant activities. These activities are also possessed by its substituted derivatives as well. The present review outlines some commonly used procedures to synthesize the isatin moiety and its derivatives, with different biological activities.