Introduction: Reduction mammaplasty can be a life-changing event for women with symptomatic macromastia. Many women experience improvement in physical symptoms, including resolution of neck, back and shoulder pain. There are other reported positive changes, including more physical activity, improved glucose control and a self-confidence. Adolescents have demonstrated weight loss following reduction mammaplasty but there is little objective data in the adult population. Methods:After obtaining institutional review board approval, eligible patients were identified in our institution's electronic record database, eRecord (Epic; Madison, WI). Eligible subjects were identified using i2b2 software for the diagnosis of macromastia (ICD-9 611.1) and the CPT code for reduction mammaplasty (19318). A retrospective study chart review was performed from June 1, 2011 to time September 30, 2015 for97 women. The mean BMI was calculated at different time intervals post-operatively, including 1 week, 1 month, 3 months, 6 months, 12 months, 1 year, 2 years and 2+ years. The BMI values for each patient were then compared to the 1 week postoperative BMI. The change was then analyzed to determine if there was any significant weight loss. Results:There is a slight increase in BMI with increasing post-operative time (mean of 31.934 at one week compared to 33.255 2+ years) although this is not statistically significant. The lowest 50% of patients based on baseline-BMI was compared with the highest 50% of patients; each group showing no significant difference over time. Similar analyses using a mixed-effects model were performed given the longitudinal nature of the data, however this also showed that there was no significant change. Conclusion:Despite well-document physical and psychological improvements following reduction mammaplasty, there is no statistically significant BMI decrease for women of all BMIs at time points from 1 month to more than 2 years when compared to their 1-week post-op BMI.