The importance of breastfeeding, especially exclusive breastfeeding (EBF) is well established for the infant, the mother and the family. The aim of this study is to assess the knowledge and practices of working mothers regarding breastfeeding and weaning using quantitative and qualitative approaches. The study was conducted in four MCH centers in Assiut city during 2010. Direct interviews were done with 43 working mothers had children aged 4 to 24 months as well as seven FGDs. 69.8% of the mothers were at the age 30 years or less. All the studied mothers knew that the breastfeeding is the best nutritional source for the baby. The majority of the mothers had good knowledge about the advantages of breastfeeding for the child and the mother. 67.4% initiated breastfeeding within the first 30 minutes after delivery. The participants in general were less knowledgeable about exclusive breastfeeding practices. There were some fault practices reported by the participants. There is a need for health education programs, which support and encourage breastfeeding particularly at a primary care level, focusing more on working mothers.