Sex differentials in infant and child mortality have been reported in many studies. These studies posit that generally the male child has better survival advantage over than the female child. However, none of these studies have examined the role of ethnicity in understanding these differentials. The question then is, to which extent does sex differences in child mortality exist in a society with patrilineal and matrilineal structures. Using Ghana Demographic and Health Survey of 2003 (GDHS, 2003), the study examines the intensity of these differentials by employing indirect method of estimation, and bivariate and multiple regression models, while giving detailed consideration to the differences in biological and behavioural/environmental perspectives as regards child health and nutritional care. It is found that among all the four major ethnic groups in the country, including the matrilineal societies, the male child has higher survival advantage than the female counterpart. The study therefore concludes that ethnicity, be it matrilineal or patrilineal, does not make any difference in sex differentials in child mortality