An observation of suspected interaction of δβ0- and α-thalassaemia, identified through careful examination of the family, is reported. The δβ0-thalassaemia was of the usual type found in Sardinia, characterised by high Hb F levels and very low levels of glycine in the isolated γCB3 peptide. The haematological findings in the double δβ0-/α-thalassaemia heterozygotes were: normal MCV and Hb A2 levels, increased Hb F (11·3 to 16·8%) heterogeneously distributed in red cells, and almost balanced α/β globin chain synthesis ratios.