Ayurveda, the Indian system of herbal medicine explains about the preparation of various types of formulations which can be used in the treatment of various diseases. Herbal oil is an important preparation which is used in the treatment of various acute and chronic diseases. The preparation of herbal oil is a complex process which takes a minimum of one day and can lead up to a couple of weeks depending upon the formulation. The present scientific study explains about the various methodologies, analysis and physico- chemical studies used to prepare a herbal oil prepared from the plant Vitex negundo Linn.using different number of days. The book sheds light on the rationality behind preparing and completing the herbal oil in different number of days is also explained. The book will act as an eye opener for justifying the importance of following the traditional method of preparation of Ayurveda medicines.