Hanid 1 recently reported on the usefulness of the fifth interdigitalow-birth-vein for intravenous infusions in the management of the very low-birthweight premature infant. The accessory cephalic vein, 2 a vein in the region of the ulnar-styloid process, has similar advantages for use in intravenous infusions in small premature infants. We report here on a survey of its presence among adults and our technique and results in cannulation in infants. Only one of 106 adults examined failed to possess this vein at least unilaterally. In the others, the vein was present bilaterally in 93 (88%) and unilaterally in 12 (11%). Of the 212 arms examined, the accessory cephalic vein was found in 198 (93%). Its size was variable, but the vein tended to be large and easily recognized if present. Its location, just medial to the ulnarstyloid process, was strikingly consistent (198/198). Only occasionally (15/198) was its proximal course,