Abstract Theories and philosophies of Unani medicine are based on the humoral theory postulated by Hippocrates 3000 yrs back.It is based on the concept of equilibrium and balance of natural body humours (blood, bile, black bile and phlegm). The imbalance in the quality and quantity of these humours leads to diseases whereas restoration of this balance maintains health of a person. Its treatment is a culmination of different regimens. Regimenal therapy is one of them. It is among the non-medicinal procedures that are used for health promotion in Unani system of medicine. Phlebotomy/Fasd (blood letting through venesection) is one of the important methods of evacuation of morbid matter from the body for the preservation and restoration of health. Though venesection is in vogue but it has been performed by physicians in various civilizations since antiquity up to the present. The Unani physicians e.g. Galen, IbnSina, Razi, Majoosi, Akbar Arzani, Azam Khan & Kabiruddin has suggested Fasd as an adjuvant regimental therapy for the management of various types of disease. Currently, therapeutic phlebotomy is approved for three main indications: haemochromatosis, polycythaemia vera and porphyria cutanea tarda. This review focuses not only on the therapeutic applications of Fasd (venesection) as described in Unani medicine but also discusses three main indications by western medicine. Possible mechanism of action and standard operative procedures of Fasd (venesection) are also discussed. Keywords: Hippocrates, Fasd, humoral theory, Regimental therapy, Phlebotomy