Introduction: The amount of milk during the first days is a determining factor for breastfeeding. Excess weight would be associated with low production, but there is no conclusive evidence on the association between the mother’s nutritional status and the amount of milk. Objective: To evaluate the pregestational, gestational and immediate postpartum nutritional status of the nursing mother and the amount of milk produced, in a population that attends the lactation friendly room of the Mayor-Méderi University Hospital between September and November 2019. Methods: Study Prospective descriptive study with mothers who attended the lactation room of the Hospital Universitario Mayor-Méderi between September and November 2019. The variables (sociodemographic, obstetric, nutritional) were determined by questionnaires and clinical history, the volume of milk was quantified per day 1 and measurements 2, 3 and 4 with three-day intervals. Descriptive and inferential analyzes were carried out. Results: The study was completed by 33 women with 27.6 ± 4.7 years. 69.7% (n = 23) had normal pre-pregnancy BMI, during pregnancy 33.3% (n = 11) adequate BMI and 30.3% (n = 10) were overweight, the weight retained after delivery was 8, 1 ± 6.5 Kg. A statistically significant negative correlation was found between the retained weight and the amount of milk (-0.4636 p = 0.0075 for the first measurement and - 0.3656 p = 0.0396 for the second). No significant differences were found in other variables. Discussion: For this population of 33 women who attended the lactation room of the Hospital Universitario Mayor-Méderi, the lower the weight retained in the immediate postpartum period, the greater the quantity of milk produced at the beginning of the study. Conclusion: Postpartum weight retention was negatively associated with the amount of milk produced. Studies with a larger sample are required to verify the associations found.