Chronic obstructive pulmonary disease (COPD) is one of the leading causes of morbidity and mortality worldwide, and represents a huge and growing economic and social burden. COPD is a multi-factorial disorder caused by environmental determinants and genetic risk factors. The beta2-adrenergic receptor (_2-AR) mediates various physiologic responses of the airways. Alterations in the ADRB2 gene have a significant physiologic role in regulating responses to exogenous _2-agonists. Understanding the genetic predisposition of COPD is essential to develop personalized treatment regimens.