This article provides an overview of the principles of good practice that underpin intravenous (IV) therapy. The indications for choosing the IV route and selecting an appropriate vascular access device (VAD) are explained. Common insertion sites for VAD placement and the care and management of VADs are reviewed. Infection control aspects of IV therapy are be highlighted, including the management of IV equipment and the importance of the nurse's role in the prevention of infection associated with IV therapy. Common complications of IV therapy are explained and strategies suggested for their prevention. The article addresses the issues associated with general IV therapy, it does not address specialist subjects such as parenteral nutrition, chemotherapy or blood transfusion.