Peripheral venous access is indicated for the administration of fluids, drugs, or if nutrients when other routes are unavailable. Central venous access is indicated if peripheral access is unsuccessful or if hypertonic, irritant, or vasoconstrictor solutions are used. Because of anatomical variations, different peripheral cannulation sites are more appropriate in different age groups. The preferred sites for long-term central venous access in infants and children are the external jugular, facial, internal jugular, saphenous veins at the groin, and subclavian veins. The practical aspects of peripheral and central venous access and the complications are discussed.