During the last 50 years penetrating keratoplasty has advanced from being considered a “high risk procedure” to a surgical inter-vention of great importance and optimum results. In a statistical study published in 1948 in a series of 417 penetrating grafts performed in different clinics in USA the percentage of success was 36.5%, whereas actually in different studies published at the end of the last century the success rate was estimated between 88 and 98%. The long term success of the procedure is basically due to better knowledge and management of the immunologic problems involved the availability of new local and systemic medications, more specialized instruments and suture material as well as considerable advances in surgical technique.