Objectives: To assess the Effectiveness of Structured Teaching Program on knowledge regarding newborn care and danger signs of new born among the Postnatal mothers in Kirumambakkam PHC, Puducherry. Methodology: Quantitative approach and a Pre experimental design was adopted. 50 postnatal mothers who fulfilled the inclusion criteria were selected for the study. Non-probability purposive sampling technique was used to select the samples. The level of knowledge was assessed by using structured knowledge questionnaire. The pretest was administered to the postnatal mothers and on the same day a structured teaching was imparted to the mothers. After 7 days the posttest level of knowledge was assessed. Results: The study findings revealed that the pretest mean score of knowledge was 24.23 with standard deviation of 5.981 and the posttest mean score was 40.52 with standard deviation of 8.902. the calculated paired ‘t’ value 10.50 was found to be statistically highly significant at p<0.001 level which showed the effectiveness of structured teaching program regarding newborn care and danger signs of new born among the postnatal mothers. Conclusion: Maternal Knowledge about neonatal care and danger signs was low inspite of the fact that RCH programme is given top priority. Therefore interventions should focus on increasing level of parental education that would go a long way to reduce neonatal morbidity and mortality