Neem (Azadirachta indica) is a member of the Meliaceae family and its role as health-promoting effect is attributed because it is rich source of antioxidant. It has been widely used various medicines worldwide especially in Indian Subcontinent in the treatment and prevention of various diseases. It possesses maximum useful non-wood products (leaves, bark, flowers, fruits, seed, gum, oil and neem cake) than any other tree species. These non-wood products are known to have anti-allergenic, anti-bacterial, anti-viral, anti-fungal, anti-inflammatory, anti-diabetic, mosquito-repellent activity, larvicidal, spermicidal and other biological activities. Earlier finding confirmed that neem and its constituents play role in the scavenging of free radical generation and prevention of disease pathogenesis. Each part of the neem tree has some medicinal property. This review gives a bird’s eye view mainly on the biological activities of the neem and some of their compounds isolated, pharmacological actions of the neem extracts and products, and plausible medicinal and therapeutical applications.