An adaptive tourniquet cuff system comprises: a tourniquet cuff having a physical characteristic and including an inflatable bladder of a length greater than the circumference of a limb at a selected location; a cuff connector carried on the cuff and communicating pneumatically with the bladder for releasably connecting to a tourniquet instrument to establish a gas-tight passageway between the bladder and the tourniquet instrument; and an identifying collar including identification means indicative of the physical characteristic and detectable by the tourniquet instrument upon establishment of the gas-tight passageway. The tourniquet instrument may supply gas to the bladder through the gas-tight passageway at a pressure sufficient to stop arterial blood flow into the limb distal to the cuff at the selected location, and may adapt its operation in response to the detected physical characteristic of the cuff.