Treating old age diseases to achieve human longevity is the greatest challenge. This abstract describes how human longevity is shortened by three old aged deadly diseases namely Cancer, Cardiovascular Diseases and Alzheimer. To prolong human life beyond one hundred years, we focus on the rational drug design to treat one old age disease one at a time. Our work began on Cancers starting in England and completed in America. More research fund is available by both The Royal Cancer Hospital of the University of London, England, and The National Cancer Institute (NCI) of America to develop drugs to treat Cancer than any other diseases. We describe below how novel drugs, like Aziridine Dinitro-benzamide (CB1954) was developed in England to treat Cancer in animals, such as Walker Carcinoma 256, a solid aggressive tumor in Rats and how the animal work is translated in humans, by developing AZQ (US Patent 4,146,622) a rationally designed drug to treat Glioblastoma, a solid aggressive brain tumor in human at the NCI. For the discovery of AZQ, our work was honored with, “The 2004, NIH Scientific Achievement Award” one of America’s highest awards in medicine.” Using the same rational approach, this abstract also describes how novel drugs could be developed on rational basis to treat Breast and Prostate Cancer to achieve human Longevity. Ethical issues achieving longevity are also described.