Photodynamic therapy (PDT) is a therapeutic modality involving the use of a photosensitizing agent activated by light to destroy tumor cells. Over the past 25 years, PDT has been shown useful in the treatment of actinic keratoses and certain nonmelanoma skin cancers, such as Bowen's disease and basal cell carcinoma. We review the current data available for PDT with systemic photofrin and topical 5-aminolevulinic acid (ALA). PDT offers many advantages including its non-invasiveness and its ability to treat multiple lesions simultaneously and is, therefore, an interesting alternative for treating certain skin malignancies.