A surgical arm rest or leg rest for supporting a patient's limb has concave tray or trough supported on a post member that extends downward. An elongated rod member situated below the tray with clamp member adjustably supports the post of the tray. A clamp member permits the rotation angle and tilt angle of the support post to be adjusted. An L-shaped support arm has a vertical arm portion adapted to be received into a support clamp mounted on the surgical table, and a horizontal arm that holds a sleeve member which supports the rod member. A locking lever on the sleeve member locks the rod member in place in the sleeve member.