In several ancient systems of medicine including Ayurveda, Greek, Roman, Siddha and Unani, Ocimum sanctum has vast number of therapeutic applications such as in cardiopathy, haemopathy, leucoderma, asthma, bronchitis, catarrhal fever, otalgia, hepatopathy, vomiting, lumbago, hiccups, ophthalmia, gastropathy, genitourinary disorders, ringworm, verminosis and skin diseases etc. The present review incorporates the description of O. sanctum plant, its chemical constituents, and various pharmacological activities.