Abstract: An automatic cuff for use with blood pressure measuring apparatus includes a cylindrical member within which a person may position his arm. A flexible band is positioned circumferentially about the inner wall of the cylinder and connected to a cable extending from the cylinder such that pulling on the cable circumferentially contracts the band in the manner of a tightening spiral. The band supports an air chamber on its inner wall and after a person's arm is snugly engaged by the band, further contraction is stopped and fluid is pumped in the fluid chamber to provide additional force in closing off circulation. After the air pressure is gradually decreased, release of the person's arm is accomplished by releasing the pulling force on the cable so that the flexible band circumferentially expands under its own natural bias.