Asymptomatic (smoldering) multiple myeloma is a heterogeneous plasma cell proliferative disorder with a variable rate of progression to active multiple myeloma or related disorders. Hypercalcemia, renal insuffi ciency, anemia, bone lesions or recurrent bacterial infections characterize active multiple myeloma. Some patients with asymptomatic myeloma develop active disease rapidly, and others can stay asymptomatic for many years. Those who are likely to progress within the fi rst 2 years of diagnosis have been categorized as having highrisk disease. The availability of novel agents in the treatment of active multiple myeloma and our better understanding of the heterogeneity of asymptomatic multiple myeloma have spurred interest in the early treatment of these patients. We have reviewed the current proposed defi nitions of high-risk asymptomatic multiple myeloma, the concerns about future therapy in view of the transient nature, remissions and toxicities of the therapies, and the eventual relapses that characterize this incurable disease.