Background: Breast reduction by the superomedial technique can relieve symptoms related to breast hypertrophy; however, as the lateral and inferior portion of the breast parenchyma is removed and displaced, reduction mammoplasty may lead to an impaired ability to breastfeed. Objectives: The aim of this study was to assess patients' ability to breastfeed after superomedial reduction mammoplasty. Methods: This was a cross-sectional study including patients treated with superomedial reduction mammoplasty between January 2009 and December 2018 at 2 tertiary hospitals in Denmark. Patients were stratified into 2 cohorts, depending on whether they had experienced childbirth before or after their reduction mammoplasty. Patients were sent specific questionnaires regarding maternity, breastfeeding before and after reduction mammoplasty, nipple sensitivity, and current demographic information. Operative details were retrieved from electronic medical records. Results: In total, 303 patients were identified as eligible for this study (37 patients giving birth after and 266 before reduction mammoplasty). Fewer patients were able to breastfeed exclusively for the recommended 6 months after reduction mammoplasty (2/37, 5.41%) compared with before (92/266, 34.59%; P < 0.05). In addition, fewer patients were able to breastfeed at all after reduction mammoplasty (18/37, 48.64%) compared with before mammoplasty (241/266, 90.60%; P < 0.001). Patients unable to breastfeed after reduction mammoplasty had lower nipple sensitivity and more breast tissue excised (P < 0.05). Conclusions: Superomedial reduction mammoplasty seems to impair the patient's ability to breastfeed exclusively for the recommended 6 months. Patients of childbearing age considering reduction mammoplasty should be made aware that reduction mammoplasty reduces their breastfeeding capacity. Level of Evidence: 4: