Exclusive breast feed is way to nourish a baby with totally human milk without any food and liquid for first 6 months. Breast feed helps to maintain immunity of baby and provide optimal growth and development. Prevalence of exclusive Breast feeding is only 38% in Pakistan. The purpose of recent study was to assess knowledge and attitude of exclusive breast feeding among lactating mothers. This study was conducted in public hospital named as The Children Hospital Lahore. Present study was descriptive cross-sectional in nature. Sample size was 384 lactating mothers. Convenient sampling technique was used to distribute the questionnaire. Data was analyzed by using SPSS version 21 and results were presented in form of figures and tables. Finding of current study reveal that a mostly 81.3% of the lactating mothers were currently breast feeding their babies. Only 37.8% of the lactating mother was exclusively breast feed and merely 35.9% started breast feeding within an hour of delivery. This study result indicate that mothers have good knowledge about exclusive breast feeding, lactating mothers have neutral attitude towards exclusive breast feeding and poor practice of exclusive breast feeding (37.8%). Present research concludes that mothers holds good knowledge, neutral attitude and poor exclusive breast feeding practices. Prenatal education should be started at antenatal units and outdoors. Health education should be provided at community level to obtain optimal exclusive breast feeding rate