This paper reports a Sardinian patient, who was a compound heterozygote for silent beta-thalassaemia and high Hb A2 beta o-thalassaemia with the clinical phenotype of mild thalassaemia intermedia; alpha globin gene mapping showed a single alpha globin gene deletion. The reduced alpha globin chain output resulted in more balanced globin chain synthesis, which in turn accounted for the mild clinical phenotype.