This is a two year retrospective analysis of 1,260 live single births at Sidamo Regional Hospital during 1989-1990. The mean birth weight was 3,243 g (SD +/- 625). There were 678(53.8%) boys and 582(46.2%) girls. The mean birth weight for boys and girls were 3,324 g (SD +/- 622) and 3147 g (SD +/- 611), respectively (t = 5.05; p < 0.001). There were significant correlations between birth weight and the age of the mother (r = 0.20; p < 0.001) as well as with parity (r = 0.15; p < 0.001). Eight per cent of the babies had birth weight less than 2,500 g. Five per cent of boys and 11% of girls had low birth weights (x2 = 8.8; p < 0.002). Higher proportion of low birth weight was also found among the young and primiparous mothers. A multiple linear regression analysis showed a significant and independent effect of maternal age and sex of the baby on birth weight. The findings are in general agreement with previous studies from Ethiopia and other developing countries. However, as this study is based on hospital data, community-based studies are needed to examine the true pattern of birth weights as hospital data may be biased.