Knowledge of breast, chest wall, and axillary anatomy is of high clinical and surgical importance in breast surgery. Disease in one of these structures requires a thorough evaluation of the anatomy of the others as they are intimately related. Careful preoperative considerations and surgical planning is essential and helps decrease surgical complications. This chapter highlights relevant anatomy of the breast, chest wall, and axilla, keeping aesthetic considerations in mind. Additionally, this chapter outlines important considerations about the evaluation of a patient prior to undergoing aesthetic breast surgery.