The health and wellbeing of children and families are the focus of the well-baby clinics (WBC), also referred to as well-child clinics. As public health clinics, they offer low-cost medical care, acting as a safety net for those who are economically challenged. Children and infants are examined for developmental delays and growth. Well baby clinic refers to a type of healthcare service created especially to track the development and well-being of healthy infants and under five children.the present study was conducted to assess the effectiveness of structured teaching programme on knowledge regarding well baby clinic among mothers of under five children.60 sample were collected by using convenience sampling technique through structured knowledge questionnaire the data collected and analysed based on descriptive and inferential statics.the result of the study showed that the post-test mean score (29.33) was high when compared to the pre-test mean (10.43) score of knowledge.the obtained “t” value (49.56) was greater than table value and df 59 which was p<0.05 level of significance, which shows that there is significant difference between pre-test and post test level of knowledge hence the formulated research H1 was accepted H01 rejected. The test revealed that there was no significant association of knowledge with selected demographic variable such as religion and educational status there was significant association of knowledge with selected demographic variable such as age of the mother, family status, monthly income, no. of children in the families and any previous knowledge regarding well baby clinic at <0.005 level of significance hence the research hypothesis H2 was accepted and H02 was rejected. The study concluded that the structured teaching programme was effective and it helps to improve the knowledge of mothers of under five children regarding well Baby clinic among