This retrospective study aimed to evaluate how reduction mammaplasty influences the bodyweight of patients 5 years after the procedure. The literature shows controversy regarding the effect of breast reduction on the progression of bodyweight. Between 1 January 2006 and 31 July 2007, 249 reduction mammaplasties were performed in the Department of Plastic, Reconstructive, and Aesthetic Surgery at the University Hospital Innsbruck. The exclusion criteria ruled out patients with oncoplastic breast reduction plasties, unilateral reduction mammaplasty, no documented preoperative weight, and bariatric procedures. The study finally included 50 women with a mean age of 44 ± 12 years. Of these 50 women, 26 (52 %) gained weight, 18 (36 %) lost weight, and 6 (12 %) remained stable during a 5-year follow-up period after the procedure. The mean weight gain was 4.50 ± 3.5 kg, and the mean weight loss was 3.44 ± 2.20 kg. The results of the study suggest that reduction mammaplasty is not a stimulus for weight loss. Although a tendency to gain weight was discovered, the weight gain compared with that of the standard population did not reach statistical significance. METHODS This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .