The recorded data on birth weight and gestational age of 16,836 babies born at Tsan Yuk Hospital in Hong Kong for the years 1970 to 1972 was analysed by computer. The means, standard deviations, and percentiles were separately obtained for nine sub-groups between 28 and 42 weeks and they were compared with similar series from Taiwan, Singapore, America and England. Chinese babies in Hong Kong were significantly heavier compared to most series between 32 and 35 weeks (p ≤ 0.001) and consistently lighter compared to all series studied between 38 and 42 weeks (p ≤ 0.001). Reasons for these findings are discussed.