Hypocupremia occurred in an adult with sickle cell anemia who received zinc as an antisickling agent for two years. The hypocupremia was associated with microcytosis and relative neutropenia. Administration of copper resulted in an increase in RBC size and leukocyte counts. We have since observed hypoceruloplasminemia of varying degrees in several other sickle cell anemia patients who were receiving oral zinc therapy. This complication was easily corrected by copper supplementation.