The adjustable surgical support system includes a lower extremity support for receiving and supporting the foot and lower leg of a patient laying supine on an operating table. A ball mount extending downwardly from the lower extremity support is selectively insertable within one of a plurality of apertures arranged in a matrix and formed in an underlying base plate. The apertures are conical in nature such that the ball mount is stable to horizontal forces when placed therein. The base plate may include at least one upwardly open channel that receives a foot rest for anchoring the adjustable surgical support system to the operating table. Surgeons and other surgical personnel may adjust the position of the foot and/or lower leg during surgery by removing and selectively inserting the ball mount into any one of the other apertures in the base plate, or rotating the same within the selected aperture.