This book is intended to present the synthesis of Novel Heteroaryl compounds by using green methodologies and their Biological applications. Wide biological spectrum and synthesis of Barbituricacid, Thiobarbituricacid, Chromones, Coumarins, Pyrazoles, Indoles, 2,4-thiazolidinediones, Isoniazide, semicarbazide and thiosemicarbazide derivatives were discussed. Various biological application of these molecules prompted us to synthesize the novel series of heterocyclic molecules by employing conventional, microwave irradiation and photochemical methods. Most of the newly synthesized compounds possess Anti Cancer, Antimicrobial and Anti tuberculosis activities. These analogs were considered to be a lead compounds for subsequent optimization in the search for novel Antitubercular agents, Anti Cancer and Antimicrobial drugs.