A patient with a leukemic phase of poorly differentiated lymphocytic lymphoma had a spuriously high automated platelet count because of cytoplasmic fragments. The number and relative percentage of cytoplasmic fragments increased during chemotherapy. The cytoplasmic fragments did not interfere with platelet aggregation using adenosine diphosphate, collagen, and epinephrine even though they were found in platelet-rich plasma. The ultrastructure of the cytoplasmic fragments is discussed. Cytoplasmic fragments as a cause of spuriously high automated platelet counts should be considered in cases of leukemic patients.