The dead leukocyte content of the blood of normal and leukemic subjects was determined by the technic of the unstained-cell counts of Schrek. A small and constant number of dead leukocytes was found in the normal blood, averaging 46 per cu. mm. In patients with chronic lymphocytic leukemia and acute leukemia, higher numbers of dead leukocytes were commonly found, ranging from normal values to as high as 4,600 per cu. mm. No correlation was found between the numbers of smudge forms on blood smears from these patients and the number of dead leukocytes. The smudge forms on blood smears appear to result from the mechanical trauma produced in making the smears. The leukocytes from chronic lymphocytic leukemia and acute leukemia appear to be much more susceptible to the mechanical forces produced in the preparation of blood smears than are leukocytes from normals and patients with chronic granulocytic leukemia.