The preference for a son continues to be a prevalent norm in the traditional Indian household. This is evident from the declining sex ratio which has dropped to alarming levels according to Census 2001 reports. In this context, we attempted to assess the knowledge of Antenatal mothers on Prenatal Diagnostic Techniques Act, and it is necessary to gear efforts against the cultural, economic and religious roots of this social malady by woman empowerment and intensive Information, Education and Communication campaigns. A descriptive study was conducted among 50 antenatal mothers of selected maternity centre in Coimbatore District, Tamilnadu. The result of the study shows that Antenatal Mothers had poor knowledge on PNDT Act. The total Mean Knowledge Score was 7.42 ± 3.04 with mean percentage was 37%. No significant association was found between Knowledge and Practice scores with Demographic variables. Positive Co-relation was found between Knowledge and Practice regarding PNDT Act (r=0.56, p<0.05). Analyzing education and attitude in our study group showed that increase in education is accompanied with an improvement in the attitude in these ante-natal women. None of the variables was significantly associated with attitude except knowledge (p<0.05). The study concluded that Antenatal Mothers had poor knowledge on PNDT Act. India has yet a long way to go in her fight against pre-birth elimination of females. The antenatal mothers will gain adequate knowledge and attitude through education and reinforcement towards PNDT Act. A concerted effort by the medical fraternity, the law, political leaders, NGOs, media, teachers and the community itself is the need of the hour.