An understanding of the chemistry of the secondary metabolites of neem plant (Azadirachta indica A. Juss) is essential and important due to its medicinal properties. Several studies have been done on the biological and pharmacological activities with a considerable progress made with respect to its biological activity and medicinal uses. The neem safety is known from its long communal ethno-pharmacological uses as a category one herbal product. It is readily available with great access to the local population at low cost and environmentally friendly. This paper attempts to give an insight into the biological activities of some of the compounds isolated, pharmacological actions of the extract, clinical studies and medicinal applications along with their safety evaluations. Issues on the active chemical constituents of various formulations, commercially available neem products, are also mentioned along with their respective application.