This paper draws out some implications of son targeting fertility behaviour for gender inequality in developing economies. It is demonstrated that such behaviour has two notable implications at the aggregate level: (a)larger number of siblings for girls (Sibling Effect), and (b)a higher within-family birth order for boys (Birth Order Effect). While the first tends to worsen gender inequality through monetary factors, the second does so in terms of non-monetary factors. Empirically testing for these effects, we find that both are present in many countries in South Asia, South-East Asia and North Africa but are absent in the countries of Sub-Saharan Africa. Using maximum likelihood estimation, we proceed to study the effect of covariates on son targeting and fertility behaviour for India, a country which displays significant sibling and birth-order effects.