Excessive weight gain after tonsillectomy has been described by a handful of studies since as early as 1988 and, in recent years, mostly with variable study design, methods, and baseline weight of the subjects. Although most otolaryngologists have likely been asked whether tonsillectomy may lead to weight gain by parents and caretakers, there has been very limited research on this issue, and certainly no causal effect has been established by existing research. Awareness and counseling based on what has been described are relevant as a part of preoperative counseling. However, it is critical that our national epidemic of excessive weight gain in children and adolescents not be simply reduced to a matter of tonsillectomy but be understood as a multifactorial and complex issue. To study this topic well requires commitment to well-designed studies assessing caloric intake and expenditure, metabolic changes, and prospective growth measurements. Mechanisms for weight gain, even if excessive during the 12 months after tonsillectomy surgery, are far from being elucidated.