This prospective, randomized, controlled trial studied the duration of upper and forearm tourniquet tolerance in 24 fit, healthy volunteers. Upper arm and forearm tourniquets were applied to either arm and inflated simultaneously. The time to request for deflation was recorded for each tourniquet. The mean tolerance for the upper arm tourniquet was 18 (range 10–26) min and for the forearm tourniquet was 25 (range 12–52) min. Under the conditions of this study, forearm tourniquets were tolerated for a mean of 7 min longer than upper arm tourniquets. The increase in tourniquet time afforded by a forearm tourniquet is clinically important in hand surgery performed under local anaesthetic.