Abstract: A temporary knee immobilizing brace or splint comprising a preformed plastic shell covering the posterior portion of the leg and knee joint with circumferential straps formed as part of the shell. Strap sections are padded internally of the shell to form non-slip garter type fastenings. The shell is relieved in the area of the knee joint to prevent contact in the area of the peroneal nerve. Positioning padding is provided along the posterior length of the interior of the shell and a positioning wedge of padding is provided at the popliteal region of the joint insuring joint flexure and minimal contact between the skin and shell of the brace, thereby allowing breathing of the skin and ease of exterior examination. A separate shield which protects the patella from injury is additionally provided.