A 25 year old Vietnamese-Canadian pregnant woman was referred to our regional perinatal center at 31 weeks gestation after a routine ultrasound examination showing fetal ascites. A diagnosis of non-immune hydrops fetalis was made, and a Caesarean section was performed two days after hospital admission. An infant with Hb Barts hydrops fetalis was delivered who expired one hour after birth. alpha-Globin gene mapping of fetal DNA confirmed the diagnosis of homozygous alpha-thalassemia with deletion of all four alpha-globin genes. Both parents were shown to have alpha-thalassemia trait with deletion of both alpha-globin genes on one chromosome. This report further illustrates the need for a simple screening test for couples at risk of giving birth to infants with homozygous alpha-thalassemia. The availability of such a test would facilitate genetic counselling and prenatal diagnosis, thereby improving the quality of obstetrical care provided to these women at risk.