OBJECTIVE To evaluate the clinical efficacy and adverse effects of Photofrin photodynamic therapy (PDT) in patients with advanced cancers. METHODS Forty patients with advanced cancers in stage IV with lumen obstruction, who failed to respond positively to other treatment regimens, received intravenous administration of Photofrin as the photosensitizer at the dose of 2 mg/kg.b.w. 48 h before PDT by 630 nm light (DIOMED) delivered through cylinder diffusing tip quartz fibers that passed through the biopsy channel of a flexible endoscope. PDT endoscopy was repeated, the necrotic tissue removed and, if necessary, the primary sites and other newly identified sites were subjected to a second exposure 8 h later. Two days after the second exposure, endoscopy was again performed and the necrotic tissue removed. Endoscopy was repeated one month after PDT and periodically thereafter as needed to treat symptomatic residual tumor. RESULTS The total rate of response to the treatment was 74% in these patients, and the rate of lumen obstruction due to the tumors decreased from 90% to 10% after PDT, with significantly improved Karnofsky performance score. CONCLUSION Photofrin PDT is effective and safe in the treatment of advanced cancer, which may relieve lumen obstruction and improve patient quality of life.