Macroglobulinemia is described in a man and 2 women. The disease was characterized by increased sedimentation rate, increase in serum globulins and the presence of serum globulins having an abnormally high molecular weight. There was a tendency to hemorrhage, lymphadenopathy, hepatomegaly, normochromic anemia, vascular disturbances of the extremities, and spontaneous jellification of the blood serum at room temperature with a slight increase in total serum protein, and abnormal plasmacy-toid cells in the marrow.