During a 10-yr. period of observa-tion, the patient''s disease followed a benign course characterized by a relapsing purpura, marked increase in the gamma globulin, rapid sedimentation rate, mild anemia, and absence of a defect in blood coagulation. Since the syndrome was first descr. by Waldenstrom in 1943 12 similar cases have been reported in the European literature. No evidence of multiple myeloma has been found after long periods of observation; no specific cause of the condition is known.