The primary goal of this study was to test the feasibility of using selective laser sintering (SLS) to fabricate a functional transtibial prosthetic socket. Prosthetic socket computer-assisted design and computer-assisted manufacturing techniques were combined with SLS technology to produce a sophisticated, monolithic, transtibial prosthetic socket. The socket combined a rigid outer shell with a variably compliant inner shell and incorporated a fitting for a pylon directly into it. The socket was manufactured for a 65-year-old transtibial amputee using a socket shape identical to his current definitive socket. A prosthesis was then assembled using the same foot as the subject's definitive prosthesis. A comparison of socket performance suggested improved comfort, greater step symmetry, and similar lower extremity joint function.