This document provides an overview of the upper limb and pectoral region. It begins by introducing the upper limb, which develops from the anterior body wall and divides into the shoulder, arm, forearm, and hand. The muscles of the upper limb are arranged in anterior and posterior compartments. The pectoral region contains the pectoralis major, pectoralis minor, subclavius, and serratus anterior muscles. It describes the anatomy of the pectoralis major and minor muscles as well as the mammary gland, its parts, blood supply, and lymphatic drainage. Key bones, fascia, and neurovasculature of the pectoral region are also summarized.