Nigella sativa Linn (Family: Ranunculaceae) is a widely used medicinal plant throughout India and popular in various indigenous system of medicine like Ayurveda, siddha, Unani and Tibb. The seeds are used as astringent, bitter, stimulant, diuretic, emmenagogue and anthelmintic traditionally. They are also useful in jaundice Intermittent fever, dyspepsia paralysis, piles and skin diseases. The Nigella seeds contain both fixed and essential oils, protens, alkaloids and saponin. Much of the biological activity of the seeds has been shown to be due to thymoquinone (TQ) is the major component of the essential oil which is also present in the fixed oil. The pharmacological actions of the crude extracts of the seeds (and some of its active constituents e.g volatile oil & thymoquinone) that have been reported include protection against neprotoxicity & hepatotoxicity induced by either disease (or) chemicals. The oil has anti-inflammatory, analgesic, antipyretic, antimicrobial, antidiabetic and antineoplastic activity. The oil decreases blood pressure and increases respiration. The present review is therefore an effort to give a detailed survey of the literature on pharmacognosy, phytochemistry and pharmacological activities of the plant.