The plasma zinc and copper and urinary zinc levels were determined by an atomic absorption spectrophotometer technic in 14 patients with hemoglobin (Hb) H disease, 34 patients with β-thalassemia/Hb E disease and 30 control subjects. Plasma zinc levels were lower and the plasma copper levels were higher in the patients than in controls. The plasma Cu:Zn ratios, a more valuable indicator of body zinc status, increased in the diseased subjects, indicating zinc deficiency. Higher urinary zinc levels in the both Hb H disease and β-thalassemia/Hb E disease suggest that chronic hemolysis is responsible for hyperzin-curia leading to zinc deficiency. The thalassemic patients with undergrowth had higher plasma Cu:Zn ratios than the patients with normal development, indicating a more severe zinc deficiency in the forme