This chapter covers the lower extremity prosthetic design and rehabilitation, and serves as a handy reference for busy practitioners to support sound clinical decision-making. It deals with basic anatomy, kinesiology, and a recap of surgical decisions principles and post-operative care for amputees. The chapter discusses common medical issues such as phantom limb sensation and pain, skin problems, and sexual and psychological considerations. It also discusses prosthetic design that differs based on patient factors such as amputation level and time since amputation. Prostheses are fabricated from distinct components that each play a role in creating prostheses that are stable, comfortable, alignable, and optimize gait and transfer of body weight to the ground. Prosthetic design depends on activity level of the individual, type of amputation, level of amputation, cause of amputation, residual limb shape and condition, time since amputation, overall health, body morphology, vocation, insurance coverage, and patient goals.