16 cases of hemoglobin E-thalassemia are reported. The interaction of thalassemia with Hb E produced a varying severity of E-thalassemia. 10 cases had a thalassemia intermedia type of clinical picture while 6 had a more severe disorder requiring regular transfusions from early childhood. 14 patients were producing Hb-A and therefore had beta+ type thalassemia whereas 1 case had no Hb-A because of beta° type thalassemia. This is in contrast to a much higher frequency of beta° thalassemia in cases reported from South-East Asia. Family studies in 1 patient revealed the interaction with delta-beta thalassemia, a situation which is rare. Mating of an Hb E-thalassemia subject with heteroyzgous beta thalassemia resulted in an offspring with severe homozygous thalassemia.