The Eighth Cooley's Anemia Symposium provided an outstanding summary of current knowledge about the thalassemia syndromes and their treatment. The known spectrum of disease is changing due to growing knowledge about the thalassemias in developing countries, due to immigration patterns throughout the world, and due to improved outcome for transfusion-dependent patients based on the development of effective chelation regimens. Much progress has been made in the development of noninvasive measurement of tissue iron concentration, which has provided new insights into the effects of iron chelation. Although subcutaneous deferoxamine remains the mainstay of treatment, oral deferiprone seems particularly effective at removing cardiac iron and preventing cardiac complications. Additional oral iron chelators are in the pipeline. Growing knowledge and insights into the mechanisms of gene regulation arising from the study of the globin gene clusters have not yet resulted in a full understanding of hemoglobin switching mechanisms. Efforts continue to develop and evaluate drugs for inducing fetal hemoglobin, although progress has been slow. In contrast, there has been substantial progress in the development of vectors for gene therapy of thalassemia and the first clinical trial has been proposed. However, proto-oncogene activation and neoplastic transformation, potential risks of vector insertional mutagenesis, have now been observed in a clinical trial for severe combined immunodeficiency, adding a note of caution. Allogenetic stem cell transplantation from a matched sibling has cured many thalassemia patients and progress is being made in the use of alternative donors for this purpose.