Intravenous therapy is available in a variety of settings and for patients of all ages. Therefore, it is essential that nurses have the clinical knowledge and technical expertise to carry out this procedure and care for patients, particularly those who are vulnerable, such as older people. This article provides an overview of the anatomy and physiology of the skin and veins. Considerations for improving venous access, selection and insertion of a peripheral cannula, and recognition, prevention and management of complications in older people are discussed. Alternative routes for the administration of fluids and medications are also explored.