Carbon and carbon deposits have been found to be increasingly useful for a wide variety of applications ranging from rocket and missile hardware to medical prosthesis. Implants and artificial organs made out of various ceramic materials are being increasingly considered in surgery. Perhaps, the most striking application is in the use of carbon for heart valve prosthesis. Surgical replacement of defective heart valves is at least well-nigh two decades old. Bioengineering studies with respect to design, material and compatibility with biological systems have made very rapid strides ever since cardiac valve replacement was conceived as a practical feasibility. Of various types of materials studied for valve prosthesis, the pyrolite carbon is now universally acclaimed as most suitable. The choice of carbon for such seemingly contradictory applications originates to the fact that it can be tailor-made to one's requirement due to remarkable variation in its crystallinity. This paper deals with the type of carbon required for medical prosthesis, its preparation, properties, characterisation and bio-compatibility investigations.