Hemolytic anemia is a clinical condition where red blood cell (RBC) destruction exceeds the ability of the body to supply new ones. In immunohemolytic anemia, the causes of the destruction are antibodies against RBC antigens. These antibodies may be either alloantibodies (isoantibodies), transfused or transferred across the placenta (e.g., in hemolytic anemia of the newborn), or autoantibodies (in AIHA). Once formed, these antibodies bind to the surface of RBCs, marking them for destruction in the blood vessels (intravascular hemolysis) and/or for elimination by phagocytosis by macrophages in the reticuloendothelial system (extravascular hemolysis). This book presents current research on the symptoms, diagnosis and treatment of AIHA. Chapter One examines oxidative stress in AIHA. Chapter Two discusses AIHA in primary immunodeficiency disorders, while Chapter Three studies AIHA in cancer disorders. Chapter Four reviews AIHA post solid organ transplants. The final chapter reviews the incidence, possible pathophysiology, clinical presentations, management strategies and challenges and outcome after an allogeneic hematopoietic stem cell transplant.