Severe limb ischemia after arterial catheterization in neonates and premature infants is a well-recognized problem. The usual treatment of ischemic injuries includes removal of the catheter and elevation of the effected limb. If unsuccessful, tissue necrosis and loss may follow. We report the case of a 700 g infant with severe distal forearm ischemia after right radial and ulnar artery catheterization. Immediate removal of the arterial line did not improve ischemia. Thirty-six hours later a brachial plexus block via the axillary approach with 0.5 ml bupivacaine 0.125% was performed resulting in rapid improvement, restricting ischemia eventually to fingers II-V as well as the distal part of the thumb. Brachial plexus blockade and active vasodilatation in tiny neonates after severe local ischemia are discussed.