Azaheterocyclic derivatives, particularly monoheteroaromatic azine, were reported as valuable scaffolds in medicinal chemistry, showing variously biological activities such as antiviral and anticancer, antimicrobials, antifungus, anti-inflammatory, antihypertensive, diuretics, antithrombics, anticoagulants, antidepressant, anxiolytics, anticonvulsant, analgesic, etc. As part of our ongoing research in the field of azaheterocycles derivatives, we present herein some core results obtained by our group in the field of monoheteroaromatic azine, especially pyridine, quinoline and fused quinoline, phenantroline, etc. focused on their medicinal chemistry applications as anticancers, antimicrobials, antifungus and antileishmanials.