Background.Although the occurrence of iron deficiency anemia and hemoglobinopathies in Vietnamese immigrants has been reported, folate and vitamin B12deficiencies have not. Proper diagnosis and effective treatment is necessary to achieve a complete correction of anemia.Methods.We retrospectively analyzed the records of Vietnamese immigrants seen in our medical clinic from 1991 to 1993. Fifty-nine anemic patients (48 females and 11 males) had low levels of red blood cell (RBC) folate and/or serum vitamin B12.Results.The patients' mean age was 37.7 ± 17 years. Mean hemoglobin and hematocrit values were 11.4 ± 0.7 g/dL and 34.4% ± 2.2%, respectively. Mean corpuscular volume (MCV) was normal in 40 patients (68%) (mean, 89.1 ± 5 fL) and low in 19 patients (32%) (mean, 69.7 ± 6 fL). Forty-four patients had low RBC folate levels (mean, 157.7 ± 41.7 ng/mL). Twenty patients had low serum vitamin B12levels (mean, 165.6 ± 47 pg/mL). Fourteen patients had ferritin levels of <20%.Conclusions.Concomitant folate, vitamin B12, and iron deficiencies or hemoglobinopathies might have been responsible for either normal or low MCV in some of our anemic patients. In this ethnic group, RBC folate and serum vitamin B12levels should be determined in all anemic patients.