Introduction: Tissue and organ transplantation is an increasingly common method of treatment. However, the needs go beyond available tissues and organs. Hematopoietic stem cells are self-renewing and serve as the origin of all blood cells in the body. The donation is completely free and safe and we can decide for that generous act at any time. It is necessary to determine the alleles of HLA system of recipients and donors before the transplantation. Goal: The aim of this thesis was to introduce and aware people about importance and beauty of the donation of tissue and organ transplantation. Materials and methods: The methods which are used to determine alleles of HLA system of recipient and donor are serological method (microlymphocitotoxicity test) and the molecular biology methods (PCR-SSO i PCR-SSP). Disscusion: Hematological diseases are becoming more common and also the need for organs is growing. Therefore, it is necessary to raise awareness and educate the population about donation and transplantation.