Triazoloquinazoline is a fused heterocyclic nucleus, formed by the fusion of two fundamental heterocyclic moieties; triazole and quinazoline. This class of compound is known for its potential as a therapeutic agent and is endowed with several pharmacological applications. Triazoloquinazoline and its derivatives have shown a variety of biological applications such as anticancer, anti-inflammatory, antimicrobial, antiviral, antihypertensive, anticonvulsant, antidiabetic, antioxidant, adenosine receptor antagonist, and significant cytotoxic activities. Hence, this privileged scaffold could act as an important candidate in the field of drug development. Many synthetic protocols have been developed to efficiently synthesize this fused heterocycle and its derivatives. Triazole and quinazoline rings fused at different positions which occurs in various isomeric forms such as, 1,2,4-triazolo[1,5-c]quinazoline, 1,2,4-triazolo[1,5-a]quinazoline, 1,2,4-triazolo[4,3-c]quinazoline, 1,2,4-triazolo[4,3-a]quinazoline, etc. This book chapter covers the synthesis of various isomeric forms of triazoloquinazoline as well as their biological activities.