This study examined anterior pituitary function and the effect of chelation therapy in 31 patients with beta-thalassemia/HbE disease. Patients were divided into those receiving chelation therapy by deferoxamine and those receiving no such therapy (control group). Pituitary function studies were repeated in both groups 18 months later. The results showed decreased pituitary responses following stimulation in 22 patients. Among these, gonadotropin and PRL responses were most affected. After 18 months, serum ferritin levels had significantly decreased in the deferoxamine group. PRL and GH responses were improved in 3 patients receiving chelation therapy without changes in other hormone responses. In contrast, no changes in pituitary responses were shown in the control group at the end of follow-up. There were 6 drop-outs (4 in the control and 2 in the deferoxamine group) and 3 deaths (2 in the control and 1 in the deferoxamine group) during 18 months. In conclusion, gonadotropin and PRL deficiencies occur most frequently in thalassemic patients. Chelation therapy for 18 months markedly reduced serum ferritin level and might preserve or improve PRL and GH secretions, but seems to have no beneficial effects on other pituitary hormone reserves.