Photodynamic therapy (PDT) involves the sequential administration of photosensitizing drugs and light for the treatment of diseased tissue. The first photosensitizer systematically evaluated for PDT was hematoporphyrin derivative (HPD). Porfimer sodium (Photofrin; manufactured by Lederle Parenterals, Carolina, Puerto Rico, under license from Quadra Logic Technologies, Inc, Vancouver, British Columbia, Canada) is a chemically related photosensitizing agent. Preliminary trials suggest a role for PDT in the treatment of primary, recurrent, and metastatic nonmelanoma skin cancers. Both HPD and porfimer sodium appear to be limited by generalized cutaneous photosensitivity, which lasts up to 6 to 8 weeks after administration. Benzoporphyrin derivative (BPD verteporfin; BPD-Quadra Logic Technologies, Inc, Vancouver, British Columbia, Canada) is a second-generation porphyrin that has shown promise in clinical studies as a safe and effective photosensitizer for PDT of non-melanoma cutaneous malignancies. Benzoporphyrin derivative is activated by a longer, more penetrating wavelength of light than is porfimer sodium, and has a shorter duration of cutaneous photosensitivity following systemic administration. The use of BPD for PDT of nononcologic conditions also had been studied. Recent trials have shown efficacy in the treatment of psoriasis by BPD-sensitized PDT using drug and light doses lower than those used for malignant tumors.