Inserting, monitoring, and maintaining peripheral venous access is an integral component of neonatal nursing care. Although complications associated with peripheral vascular devices are typically minor, some infants may experience life-threatening sequelae or serious and prolonged alterations in function. This article provides a review of the relevant anatomy and physiology of the peripheral venous system, techniques for maintaining catheter security, and guidelines for conducting a systematic physical assessment. The most commonly occurring complications, such as infiltration, phlebitis, and occlusion, are described. The etiology of the complications, signs and symptoms, and key evidence-based prevention strategies are outlined.