Hematologic evaluations of 254 Southeast Asian refugee children from 163 families are reported. Hemoglobin E trait was common in Cambodians (19%) and Laotians (18%), but rare in Vietnamese (1%). beta-Thalassemia trait was most prevalent in Vietnamese (8%), and less common in Cambodians and Laotians (3%). alpha-Thalassemia was prevalent in all three groups. Hemoglobin concentrations and mean corpuscular volumes seen with hemoglobinopathies were compared with those of Southeast Asian children with normal hemoglobin. Both Hb AE and Hb EE were shown to be benign conditions resulting in microcytosis and mild, if any, anemia. In children with Hb AE, mean corpuscular volume ranged from 64 to 78 ft and Hb E from 27% to 34%. In those with Hb EE, microcytosis was more marked (50 to 63 ft). In 15 children with Hb EE, there was a delayed fall in fetal hemoglobin, which can cause diagnostic difficulties in infants.