Introduction: Breastfeeding (BF) practices remain the cornerstone to reduce infant and child morbidity and mortality in world including India. According to UNICEF exclusive breast feeding in first six months of life can reduce under-five mortality rates in developing countries by 13%. Aim: This study was conducted to assess the knowledge and practices regarding breast feeding among mothers of under-five children in Shimla city. Materials and Methods: A descriptive cross-sectional study was conducted among the mothers of under-five children residing in the Shimla city to determine their knowledge and practices level related to breastfeeding. Out of 25 wards of Shimla city 10 households from each ward were selected for interview by simple random sampling. Results: Among 250 subjects interviewed, mean age was 25.18± 5.19 and 68.4% were from nuclear family, and mostly (64.2%) from lower middle and middle SES class. Nearly (60.4%) of mothers undergraduate, (56.8%) housewives, and (63.6%) with parity one. Overall knowledge about breastfeeding was 74% but adequate practice was only 62%. Being a working women had more prevalence of inadequacy of knowledge. Conclusions: Our cross sectional study concludes that the overall knowledge about breastfeeding is not translated into action. We recommend behaviour change communication to enhance BF practices, and flexible working hrs for working women and crèches at working place for them.