The recent provisional census figures for Rajasthan show an alarming drop in sex ratio in the 0-6 age group from 909 in 2001 to 883 in 2011. While it was 916 in 1991, a fall of 7 points (0.76%) in previous decade and a much higher decline of 26 points (2.86%) in present decade are indicative of a clear bias against girl child in Rajasthan. Using Pooled OLS and Quantile Regression estimates for the last three decennial censuses, the paper is an attempt to examine the determinants of declining child sex ratio in Rajasthan. A key result we obtained in pooled OLS, suggests that one percentage point increase in male literacy has reducing effect on the juvenile sex ratio by on and average 0.14 percent in the districts of Rajasthan during 1991-2011. This finding is robust and successively increasing in all single decadal year OLS estimates. This means that with an increasing level of male literacy, strong son preference attitude and use of ultrasound machines for female foeticide have been flourishing freely in the state since last two decades The revealing Quantile Regression results indicate that the male literacy rate has an insignificant effect at the 0.05 quantile and it turns significant and increasingly negative at successively higher quantiles, while the female literacy and other infrastructural facilities like safe drinking water have positive and significant effect on the upper tail of juvenile sex ratios. The most public intervention such as strengthening female education and availability of safe drinking water facilities are essential to increase the juvenile sex ratio in the state but not sufficient. Strict enforcement of PCPNDT Act and laws to provide women the right to inherit ancestral property are an utmost need for balancing child sex ratio in the state.