Cinnoline is an aromatic heterocyclic compound having a wide range of pharmacological actions like antibacterial, antifungal, anti-inflammatory, anti-tuberculosis, antiepileptic, antidepressant, antitumor, antihypertensive, antianxiety activities. Cinnoline is a fused six-membered ring with two nitrogen atoms as heteroatoms which is an isosteric derivative to quinolone or isoquinoline. This heterocyclic nucleus is the least condensed one and is having a special interest in the synthetic research field. This review discusses the biological activities of cinnoline compounds with different substitutions.