A tissue stabilizer includes a pneumatic rigidifying bladder which is flexible when at ambient pressure and rigid when at negative pressure or evacuated. Structure such as straps with hook-and-eye fasteners attaches the rigidifying bladder to tissue to be stabilized, such as a broken arm. When positioned on the tissue, the bladder is evacuated, thereby rigidifying the bladder and supporting the tissue. The tissue stabilizer may be configured for use in surgical procedures, such as performing coronary artery bypass grafting (CABG) on a warm, beating heart. In a cardiac embodiment, the tissue stabilizer includes an attaching bladder with a plurality of openings. When suction is applied at a port of the attaching bladder, suction is applied at the openings, which is utilized to attach the stabilizer to the epicardium of the heart. Once in position on the heart, suction may be applied at a port of the rigidifying bladder. When rigid, the heart may be moved as desired to perform CABG procedures.