Aggressive treatment has improved the long-term outcome of extremely low birth weight (ELBW) and low birth weight (LBW) neonates, but it has also increased the risk of iatrogenic lesions. The aim of this paper is to evaluate the incidence of vascular injuries observed in the neonatal intensive care unit of our hospital. From 1987 to 1994, 2898 neonates were admitted to the neonatal intensive care unit; 335 of them were either LBW or ELBW (11.5%). A review of the charts of these neonates disclosed nine neonates (four male, five female) with vascular lesions (2.6%); the mean gestational age of these patients was 28.7 weeks (range, 24 to 33 weeks), the mean weight at birth was 880 g (range, 590 to 1450 g), and the mean weight at diagnosis was 1825 g (range, 1230 to 2700 g). In the same period, 10 neonates with vascular injuries were reported in the 2563 neonates who weighed more than 1500 g (0.3%). The injuries observed in LBW and ELBW group were arteriovenous fistulas (two bilateral) at the femoral level (six neonates), carotid lesion (one neonate), and limb ischemia (two neonates). Injury was associated with venipuncture in seven neonates, and with umbilical catheter in one; the case of carotid lesion was related to surgical error. No general symptoms were observed. The carotid lesion and five arteriovenous fistulas were repaired by microsurgical techniques; one case of limb ischemia was resolved with thrombolytic drugs, whereas an amputation at the knee level was required in the other after 10 days of medical treatment. One neonate with an arteriovenous fistula was just observed according to the parents' wishes. At clinical and echo-color Doppler follow-up, seven of nine neonates had normal vascular function without sequelae. In our experience, LBW and ELBW neonates are at greater risk than older neonates of the development of iatrogenic vascular lesions. We advocate aggressive microsurgery, medical treatment, or both to obtain good results and prevent late sequelae.