Neem has become important in the global context today because it offers answers to the major concerns facing mankind. Azadirachta indica is a fast growing evergreen popular tree found commonly in India, Africa and America. This review gives a bird’s eye view mainly on the biological activity and its preventive-promotive medicinal uses and applications over all this review also tell you that how the “neem is the one solution of thousand problems”, like Antiallergenic, antidermatic, antifeedent, antifungal, anti- inflammatory, antipyretic, antiscabic, cardiac, diuretic, insecticidal, parricidal, nematicidal, spermicidal and other biological activities.