Background : Breast feeding, the most natural way of infant feeding to satisfy nutritional, metabolic and psychological needs of the baby. Objectives : To assess the knowledge of breast feeding among primi- gravida mothers attending ante-natal clinic and to determine the association between socio-demographic variables with their knowledge. Materials and Methods : Hospital based cross sectional study was conducted at Ante-natal clinic of Krishna Hospital and Medical Research Center, Karad district Satara. Pre-tested structured proforma used to collect information from 590 married primi gravid mothers attending anti-natal clinic during study period by utilizing personal interview method. Statistical Analysis : socio-demographic frequency percentage distribution, knowledge scoreing and statistical association was analysed by using chi-square test. Results: Out of 590 primi gravida mothers, 59.66% showed fair quality of knowledge about breast feeding. knowledge about rooming in, family support for breast feeding & burping after breast feeding was 97.7%, 95.4%, 93.5% however weaning, colostrums feed, hazards of bottle feeding and prelactal food was 84%, 82.7%, 75.5% and 54% respectively. Statistical association was existed between age, education, religion, socio-economic status & occupation of respondents with their knowledge about breast feeding (?(2)=151.52, p < 0.0001*; ?(2)=211.27, p<0.0001*; ?(2)=133.91, p < 0.0001*; ?(2)=35.59, p < 0.0001* and ?(2)=131.04, p<0.0001*) respectively. Conclusion: knowledge of breast feeding among primi gravida mothers attending ANC clinic was of fair in quality.