Immunomodulatory (IMiDs) drugs are a new class of anticancer agents that has made a tremendous impact on the treatment of patients with various malignant diseases, including blood cancers and several cancers of the solid organs. Their popularity in prescribing is based on several important characteristics including: (1) oral bioavailability, (2) non-chemotherapeutic, (3) extremely well-tolerated in all age groups, (4) ability to activate patient's own immune response against cancer, (5) ease of combination with other agents such as chemotherapy resulting in higher responses as well as (6) variability of anticancer activity and a number of cancers. While there is a lot of literature published on these agents, there is no textbook that provides a comprehensive resource for clinicians and researchers regarding these agents and their rapidly emerging role in cancer medicine.