The emergency blood needs of 449 patients were met by supplying 1,717 uncrossmatched units of either red blood cells (RBC) type specific Whole Blood or group O RBC. The RBC were all Rh positive, and 601 units were transfused to 262 untyped patients. None of the patients presented with anti-Rh antibodies. Only 20 patients who were Rh negative received group O Rh positive RBC, and most of these patients were male. There were no acute hemolytic reactions or sensitizations of young females. Group O Rh positive RBC is our first choice to support patients with trauma who cannot wait for type specific or crossmatched blood. Those who do survive the emergency conditions can be reverted to blood of their own type without problem. Acceptance of Rh positive emergency transfusions by physicians giving emergency care can prevent unbalanced shortages in a regional blood supply system.