Hematologic malignancies are cancers that occur in the blood, bone marrow, and lymph nodes. There are three types of hematologic malignancies, namely, leukemia, myeloma, and lymphoma. Leukemias are blood cell cancers, myeloma is plasma cell cancer and lymphomas occur when lymphocytes develop abnormally and become lymphoma cells. These are caused when there is an abnormal growth of cells. Some of the common signs and symptoms of hematologic malignancies are fatigue, fever, swollen lymph nodes, bone pain, weight loss and shortness of breath. Hematologic malignancies can be diagnosed through blood test, bone marrow biopsy, physical exam, imaging test, and lymph node biopsy. Leukemia and lymphoma can be treated by chemotherapy, radiation therapy, biological therapy, targeted therapy, bone marrow transplant and stem cell transplant. This book elucidates the concepts and therapies in relation to hematologic malignancies. Different approaches, evaluations, methodologies, and advanced studies on these diseases have been included in it. This book will serve as a reference to a broad spectrum of readers.