Artificial organs have come a long way since the first dialysis machine, the rotating artificial kidney, was invented in 1944 by Willem Johan Kolff, who is known as the ‘‘father of artificial organs’’. At that time he met stiff resistance from his hospital superiors but his persistence paid off and a million saved lives have been attributed to his first invention. He was indeed the first to mix medicine and engineering. An artificial organ is any machine, device, or other material that is used to replace the functions of a faulty or missing organ or other parts of the human body. Some body parts are more of a challenge than others. The heart has one purpose and it is to pump blood; however, the liver has biochemical and physiological functions which are difficult to simulate. The implantation of an artificial organ is critical because of the patient life dependency on the artificial organ itself. The treatment of choice is organ transplantation, however, transplant candidates face a long waiting time and many die while on the waiting list. In addition there are patients who are excluded from transplantation because of age or presence of other diseases. This book p- sents an overview of the current state of knowledge of artificial organs including the liver, pancreas, kidney, heart, cochlea, skin, stem cells, composite tissue allograft, and sphincters.