• We present an experience with indwelling peripheral arterial catheters in preterm and term neonates. During a 12-month interval, 158 peripheral arterial lines were inserted In 115 infants. Eightyeight infants required a single line while 27 infants required more than one line. Ninety-one catheters (57.6%) were electively removed, and 67 (42.4%) had to be discontinued prematurely. Vessels used included 110 radial arteries (69.6%), 27 posterior tibial arteries (17.1%), and 21 temporal arteries (13.3%). There were only two major complications (1.27%), both related to infections. The technique is described in detail. In our experience, with appropriate precaution, peripheral arterial cannulation has been a safe and reliable alternative to umbilical arterial catheterization.