Photodynamic therapy was introduced over 20 years ago with great promise in the field of oncology. The theory was simple: inject a biologically inert but photosensitive drug into a test subject and the drug would be preferentially taken up by tumor cells. Activation of this prodrug by laser light would theoretically result in a complete tumoricidal effect. Tumors of the skin, urogenital tract, and mucosa of the upper aerodigestive tract and bronchi were targeted due to the ease of access by the laser light. In general, results of multiple studies have been mixed and unpredictable. This review updates the reader on the status of this technology.