Herbs and related natural products such as spices are the oldest and most widely used form of medicine in the world. The use of herbs for the treatment of disease and the promotion of well-being can be traced back in many cultures at least 2,500 years. The most comprehensive and reliable data on the use of herbal medicine in the United States come from the National Health Interview Survey. Herbal medicines, also known as botanicals or phytotherapies, are one component of the range of natural products sold in the United States as dietary supplements. Nursing can play a critical role in patient assessment in regards to use of herbal medicines and in the education of patients on the safety and use of medicinal herbs. This chapter addresses three of the most important herbs (Echinacea, Ginkgo, and St. John’s wort) from an evidence-based perspective.