Objective: Identificar los distintos grupos sanguíneos diferentes al sistema ABO y Rh más inmunogénicos y su impacto en los servicios de medicina transfusional. Methods: A comprehensive review of recent literature (2019-2024) on less common blood group systems was conducted, opening up aspects such as genetic bases, clinical applications, and the integration of modern technologies, such as molecular biology, to improve accuracy in diagnosis. antibody detection. and antigens. The immunogenic characteristics of these groups were analyzed and the variability of their prevalence between populations was analyzed. Result: Advances in techniques for identifying less common blood groups have significantly improved the ability to detect them, which is crucial for avoiding adverse transfusion reactions and for the proper management of hemolytic diseases. However, challenges remain related to the cost and accessibility of these technologies. The review concluded that it is essential to continue developing and refining techniques to ensure transfusion safety and optimize patient care, providing an open and updated view of blood systems in transfusion medicine.