Background: Exclusive breastfeeding (EBF) for the first 6 months of life improves the growth, health and survival status of newborns. Breastfeeding has been accepted as the most vital intervention for reducing infant mortality and ensuring optimal growth and development of children. Objectives: The general objective was to identify the factors affecting exclusive breastfeeding among working class women in selected wards in Egbedore Local Government in Osun state, Nigeria. Methodology: This was descriptive cross-sectional study. Leslie Kish formula was used for sample size calculation and multistage sampling was used in selecting 316 working class women for the study. A structured, self-administered questionnaire was used for data collection. Data was analyzed using SPSS version 21.0 and level of significance was set at 5%. Results: 58% of the respondents were between the ages of 25-30. 72% demonstrated good understanding of exclusive breastfeeding based on the 6 months WHO recommendation for exclusive breast feeding, 25.9% had a fair knowledge and awareness of exclusive breastfeeding. 63.3% of the working class mother has a good practice of exclusive breast feeding, 19.6% of the women moderately practices exclusive breastfeeding while 17.1% poorly practices exclusive breastfeeding. Less than 3-months maternity leave for mothers, lack of crèche closer to place of work and lack of breastfeeding break were identified as barriers to exclusive breastfeeding practices among the working class women. The findings demonstrated a significant relationship between knowledge and practices of exclusively breastfeeding among working class women (P-value .009). Conclusion: This study demonstrated that working class women had good knowledge of exclusive breastfeeding and this influenced their breastfeeding practices. A good knowledge was associated with favorable attitudes to the practice of exclusive breast feeding. To derive long-term benefits from early childhood nutrition, interventions should focus on health education and community-based sensitization programs on the needs for mothers to engage in exclusive breast needing for global development.