Cancer is scourge afflicting mankind from the time immemorial, and is a group of more than one hundred diseases. In fact, the cancer is major killer in most of the countries. Several environmental factors, including air, water and industrial pollutants, environmental chemicals and radiations, etc. may cause various types of cancer. In spite of the spectacular advances made by Medical Science in the present century, treatment of cancer remains an enigma. However, since time immemorial, the medicinal plants and their products (or herbal drugs) have been used for the treatment of various types of cancer. In the indigenous system of medicine, plants have been used against many kinds of cancer, for over 2000 years all over the world. More than 1,000 plants have been found to exhibit significant anticancer activity. Hence, now it is doubtless that plants are the most vital source of many compounds that possess significant anticancer activity. Considering the above facts, this research book “Treatment of Cancers by Medicinal Plants” has been put forth to give the recent knowledge regarding different carcinogens causing various cancers, and their treatment by different medicinal plants/herbal drugs as discussed in the eight chapters of the book. This publication will definitely serve as resourceful referral to the scientists, oncologists, academicians and students of Life Sciences, including Veterinary, Medical, Ayurvedic and Pharmacy.