Obesity and specimen weight have both been associated with a higher incidence of complications for patients undergoing reduction mammaplasty. However, obesity has been arbitrarily and inconsistently defined, and the degree of obesity has not been considered in these previous studies. Because insurance companies are increasingly demanding weight loss before authorizing surgery, the relationship of obesity and breast size to complications is of great importance. Upon critical review of the literature, a number of fundamental questions remain unanswered. If complications are more frequent in the obese patient, are these complications directly proportional to the degree of obesity? Also, if the patient is required to lose weight before surgery, is weight loss effective in reducing complication rates? In an attempt to clarify these issues, 395 patients who underwent reduction mammaplasty over a 10-year period were reviewed retrospectively. Patients were arbitrarily divided into five groups in which, depending on their degree of relative obesity, they were classified as less than 5 percent, 5 to 10 percent, 10 to 15 percent, 15 to 20 percent, or greater than 20 percent above average body weight. To evaluate the relationship of specimen weight to complications, patients were also arbitrarily divided into five groups according to weight of the breast reduction specimen, which was classified as less than 300 g, 300 to 600 g, 600 to 900 g, 900 to 1200 g, and greater than 1200 g reduction per breast. Complications were then divided into local and systemic and major and minor. When bilateral reductions alone were analyzed (n = 267), there was a statistically significant increase in complication rate in the obese (p = 0.01). However, when the obese population was further subdivided according to their degree of obesity (less than 5 percent, 5 to 10 percent, 10 to 15 percent, 15 to 20 percent, and greater than 20 percent above average body weight), no further correlation was found. However, the relationship between specimen weight per breast and complications was much stronger with a direct correlation existing between increasing specimen weight and the incidence of complications. Although this study has shown that patients who are average body weight have fewer complications than obese patients after breast reduction surgery, it has not shown an increasing incidence of complication with increasing degrees of obesity. The implications of these findings and their relationship for denying patients surgery on the basis of weight alone are discussed in detail.