Cord blood from 6578 neonates of Mediterranean origin born at The Royal Women's Hospital, Melbourne, over a five-year period was screened for alpha-thalassaemia by haemoglobin electrophoresis for haemoglobin Bart's (Hb Bart's), and 47 cases of the abnormal haemoglobin were detected (an over-all incidence of 0.71%). Hb Bart's was detected in Turks (2.9%), Cypriots (2.8%), Egyptians (2.0%), Lebanese (0.8%), Greeks (0.7%), Italians (0.5%), and Yugoslavs (0.2%). The mean level of Hb Bart's for the group was 4.6%. Four cases of alpha/beta thalassaemia were also detected during this survey.