Mothers of cesarean section need more support for breastfeeding. The purpose of this study was to use Bristol's tool for lactation counseling on the breastfeeding status in mothers undergone Cesarean section. Methods: In this quasi-experimental study,80 primiparous women after cesarean section In Fatemieh Hospital of Hamedan in year 2018 were selected by available sampling method and assigned to two groups of test (pairs) and control (individual days) (40 persons per group). In two groups, the researcher reviewed the Bristol Breastfeeding checklist, assessed the breastfeeding status, nuchal infant, milk swallowing and infant suction and, based on the need, a breastfeeding counselor was provided in the test group. The counseling was given to the mother during the first 2 hours, 2 days, 10 days and one month after delivery. During this time, the control group received routine care only. The lactation continuity questionnaire was completed for both groups during the four months after delivery. Results: Two groups had no significant differences in demographic variables (P > 0.05). There was a significant difference between the mean duration of lactation during the four months postpartum (P <0.001). The mean of Bristol instrument scores in the first session did not have a significant difference between the two groups, but in the second, third and fourth sessions after delivery, there was a significant difference between the two groups (P <0.001). Conclusion: The Bristol tool is a good tool for evaluating mothers breastfeeding.