Topical photodynamic therapy (PDT) is used to treat nonmelanoma skin cancers, such as actinic keratoses, Bowen's disease, and basal cell carcinoma (superficial and nodular). This article presents up-to-date, practical, evidence-based recommendations on the use of topical PDT using 5-aminolevulinic acid or methyl aminolevulinate for the treatment (and prevention) of nonmelanoma skin cancers. A systematic literature review was conducted (using MEDLINE), and recommendations were made on the basis of the quality of evidence for efficacy, safety/tolerability, cosmetic outcome, and patient satisfaction/preference. Topical PDT is highly effective in the treatment of actinic keratoses, Bowen's disease, superficial and thin nodular basal cell carcinomas, with cosmesis typically superior to that achieved with existing standard therapies. PDT may also be a means of preventing certain nonmelanoma skin cancers in immunosuppressed patients.