Tulsi (holy basil), “Queen of herbs” is the blessing of our nature. There are different types of tulsi plants. Among them, the Ocimum sanctum is very popular in the culture of the Hindu religion and the perspective of ethnomedicine. The medicinal uses of tulsi were started in ancient times. Its medicinal values were described in the Indian classical herbal medicinal book “Charaka Samhita”. The modern civilized society still uses this valuable plant as alternative and complementary medicine. The aqueous or alcoholic extract of Ocimum sanctum contains flavonoids, alkaloids, polyphenolic compounds, eugenol, ursolic acid, carvacrol, linalool, etc. Different parts (leaves, seeds, stem), or extract (herbal tea, juice) of tulsi are used for medicinal purposes. The biopotential compounds of tulsi are active for the prevention and cure of many illnesses like cough, bronchitis, asthma, common cold, fever, hepatic diseases, skin diseases, arthritis, and digestive disorders. Applications of tulsi as herbal medicine improve the various pathological conditions without any major complications or side effects. The present paper is related to the botanical description of the Tulsi plant, its bioactive components, their pharmacological activities.