Background: The World Health Organization (WHO) and the United Nations Children’s Fund (UNICEF) strongly recommend exclusive breastfeeding (EBF) for the first six months of the infant's life to achieve optimal growth, development, and health. This study aimsto estimate the prevalence of EBF up to the age of six months and to identify the factors associated with EBF among mothers that attended the Well-Baby Clinic,Al-Nawariyah Primary Health Care (PHC)Center, Makkah, Saudi Arabia in 2018. Methodology: A cross-sectional study of125 mother swho attended the Well-Baby Clinic, Al-Nawariyah PHC Center, Makkah, Saudi Arabiain January 2018,using a validated self-administered questionnaire in the Arabic language. Result: A sample of 125 mothers, 52.4% of which used mixed feeding, 25.4% used artificial feeding, 16.6% used breastfeeding with water and other supplements, and 5.6% used EBF during the first six months after birth. Mothers who were properly educated on EBF were more likely to practice it compared to those who received improper or no education about EBF (16%, 0%, and 7.1% respectively; p=0.006). The top three barriers to EBF were insufficient breast milk (37.6%), the belief that breast milk alone is not enough for growth (24.8%), and the lackof awareness about the importance of EBF (20.8%). There is no significant relation between EBF and any of the following: mother’s age, mother’s education level, employment status, and family income. Conclusion: The current study results conclude that EBF rate is significantly low (5.6%). The present study showsa significant relation between EBF and proper health education regarding EBF.