Introduction: Despite the numerous emphasis on the importance of exclusive breastfeeding for the first 6 months of life, but studies have indicated that it is low in Iran. In this study, we investigated the economic factors affecting exclusive breastfeeding in the first 6 months of life. Methods: The study population included 6-12 months old children who were referred to Arak healthcare centers with their mothers for vaccination and healthcare. Sampling was performed according to Cochran formula. The questionnaires were completed by asking mothers and also visiting family documents. Kaplan-Meier survival analysis was used to investigate the relationship between exclusive breastfeeding and household socioeconomic variables. Adjusted and unadjusted odds ratios for factors affecting exclusive breastfeeding and also the relationship between household variables and breastfeeding were assessed using multivariate logistic regression. Results: Exclusive breastfeeding decreased from 85.1% to 46.2% with increasing in age from 0 to 6 months. Working mothers, mothers with higher education and physical activity had breastfed higher than others their infants up to 6 months (p<0.05). There was no significant relationship between sex of child, household income, maternal BMI, pregnancy complications, previous abortion and type of delivery with exclusive breastfeeding (p>0.05).Conclusion: In spite of high emphasis on the importance of exclusive breastfeeding in the first 6 months of life, but it has not been met. Findings from this study contribute to the growing body of research on the social determinants of breast feeding.