Objective: To demonstrate that pain affects the goodness of breastfeeding. Materials and Methods: Seventy-nine patients were interviewed regarding satisfaction in breastfeeding, tiredness, uterine pain, nipple and other pain, and analgesic use at day three and at first, second, third, and fourth week after birth. Data regarding the mode of delivery were recorded from medical charts. Milk formula supplements, bottle use, pacifier use, and nipple shields use were considered as variables suggesting unsuccessful breastfeeding. Results: At third day after delivery, it appeared that analgesic use was significantly associated with milk formula supplementing, bottle use, less satisfaction in breastfeeding, and more tiredness. At first week after delivery, the presence of pain differing from nipple and uterine pain, was more likely associated with milk formula supplementing, bottle use, pacifier use, less satisfaction in breastfeeding, and more tiredness. At third week after delivery, nipple pain was directly related to tiredness, while it increased the odds of adding milk formula and using a bottle. Conclusion: Pain affects the goodness of breastfeeding.