Background: The target by the Indonesian public health services to obtain at least 50% exclusively breastfeed babies during the first 6 months has not been achieved, due to the increased in infant morbidity. This study aims to determine factors associated with exclusive breastfeeding. Design and Methods: The cluster random sampling method was used to obtain data from a total of 273 babies in the first 1000 days of life i.e. aged 6-24 months and analyzed using linear regression at α= 0.05. The data obtained were based on exclusive breastfeeding using maternal age, education, family income, frequency of antenatal care, nutritional status before pregnancy, place and mode of delivery, gestational age at delivery. Results: The result showed that exclusive breastfeeding was significantly affected by nutritional status before pregnancy based on MUAC (P=0.15) and BMI (P=0.047), family income (P=0.047) and initiation of early breastfeeding (P=0.001). Conclusions: In conclusion, nutritional status before pregnancy tends to benefit the family income, therefore, initiating early breastfeeding need to be improved for successful exclusive breast-feeding.