Herbal medication has attracted much attention in recent years and is being used as an alternative to chemical medicines. Some evidence supports the positive effects of medicinal plants in the prevention and treatment of different types of diseases. Thymoquinone (TQ) is the most abundant component of Nigella sativa seeds, and most of the properties of Nigella sativa are attributed primarily to TQ. It belongs to a class of naturally presenting phenols, chemically known as 2-isopropyl-5-methyl benzo-1, 4-quinone (C10H12O2), is a dark yellow crystalline monoterpene diketone, abundantly found in the seeds of Nigella sativa. Besides Nigella sativa, TQ is an active ingredient of several plants as Juniperus, Monarda, Coridothymus, Agastache, Satureja. It has been reported to possess various beneficial therapeutic effects including anti-oxidant, anti-inflammatory, anti-microbial, anti-diabetic, hepato-protective and cardioprotective effects. It is significant to say that TQ may be effective as a powerful contender of natural origin with therapeutic potential against an array of maladies.