The objective of this cross sectional study is to look at determinants of birth weight and their association with the gender of the baby in 2,795 full term children living in the occupied Palestinian territory, derived from a stratified random sample of 2,994 households in the West Bank and 2,234 households in the Gaza Strip. The response rate was 85%. Multivariable analysis using analysis of variance for mixed models showed that sex and birth order, maternal age and education and to a lesser extent region were determinants of birth weight for all children. The effect of maternal education on birth weight differed for female and male infants, tending to be relatively unchanged for male infants and with mean birth weights increasing with maternal education in female infants. The effect of birth order differed by maternal age, with mean birth weight increasing with maternal age for first and second births; but being unaffected by maternal age for infants of birth order greater than two. We conclude that birth weight is influenced by common biological determinants across cultures, but is also influenced by social, ethnic, and environmental factors that are culture specific, of which some might be gender related.