Photodynamic therapy (PDT) is a "drug and device" therapy that combines the use of a photosensitizing agent and a photosensitizer (a drug that selectively accumulates and is preferentially retained in dysplastic or neoplastic cells). When activated by light of a specific wavelength in the presence of oxygen, the photoactive compound produces rapid cell death in the target tissue. While studied in nearly every area of medicine, PDT has been applied most extensively in the treatment of Barrett's mucosa, dysplasia, and early and advanced cancer of the esophagus. This article represents an extensive survey of literature to review the experience gained with PDT and to assess its clinical value in the management of esophageal diseases.