From centuries ago man has been using herbs for medicinal purposes, in traditional system of medicine like Unani, Ayurveda, Chinese medicine number of herbs and drugs of plant origin are found to be useful in curing of variou s ailments. Oak galls (Mazu) is an out growths formed on the young twigs of the dyer's oak, Quercus infectoria (Fagaceae), as a result of the deposition of the eggs of the gall-wasp Adleria gallae-tinctoriae Olivier, this is used for medicinal purposes before escape of in sects in dried form as described by classical Unani literature. Keeping in v iew of it this literature is reviewed about medicinal properties of Mazu described by ancient Unani sch olars along with latest research on it this review paper is formulated and an attempt is mad e to correlate properties of Ma zu with latest scientific research.