Molecular characterization of the compound heterozygous condition – Gγ(Aγδβ)o/β-thalassemia – in four families showing mild β-thalassemia intermedia was carried out using DNA amplification techniques. Using the Amplification Refractory Mutation System (ARMS) to confirm the β-mutations and DNA amplification to detect the 100-kb Chinese-specific Gγ(Aγδβ)o-deletion, two families were confirmed to possess Gγ(Aγδβ)o/β-thalassemia with the IVSII No. 654 β+-allele. In the third family, the Gγ(Aγδβ)o-deletion was confirmed in the father and the mother was a β-thalassemia carrier with the cd 41–42 βo-allele. Their affected child with Gγ(Aγδβ)o/β-thalassemia was found to be transfusion dependent. The same Gγ(Aγδβ)o-deletion and β-thalassemia (cd 41–42) was also confirmed in a fourth family. In addition, the mother was also diagnosed with Hb H disease (genotype -α3.7/–SEA). Both the children were found to possess Gγ(Aγδβ)o/β-thalassemia but they were not transfusion dependent and this could be due to co-inheritance of α-thalassemia-2 (genotype-α3.7/αα) in the children together with their compound heterozygous condition.