Anticancer drugs refer to drugs that are used for treating cancerous or malignant diseases. They are classified into several categories, including antimetabolites, hormones, alkylating agents and natural products. Preclinical research, clinical research and post-clinical research are the three primary steps in the development of a novel drug. Clinical trial evaluation, in vivo confirmation, and in vitro cytotoxicity on cancer cells are the major assessment methods used while creating an anticancer drug. The evaluation of cytotoxicity towards cancer cell lines is a popular method for discovering anticancer agents. New cancer drugs can be discovered in a variety of ways including testing of animals, plants and fungi, understanding the chemical structure of a drug target, unintentional discovery, developing drugs that are similar to existing drugs, and researching the biology of cancer cells. This book unravels the recent studies on anticancer drug discovery and development. Those in search of information to further their knowledge will be greatly assisted by it.