BACKGROUND Chest wall progression of breast carcinoma after failure of salvage surgery, radiation, and chemohormonal therapy is a quagmire with limited therapeutic options. Because photodynamic therapy (PDT) offers excellent results in cutaneous lesions, PDT may play a role in this indication. However, to the authors' knowledge, published data for this subgroup of patients using the only commercially available photosensitizing agent, Photofrin, often show high treatment morbidity, limiting PDT's usefulness. The authors report the feasibility of decreasing the photosensitizer drug dose as a means of exploiting photobleaching kinetics to improve the therapeutic ratio for these individuals. METHODS One hundred two chest wall sites were treated with PDT after failure of multimodality salvage therapy. In these 9 patients, lesion size ranged from 0.57 to 9 cm. Photodynamic therapy consisted of outpatient intravenous infusion of 0.8 mg/kg of Photofrin, followed 48 hours later by 630 nm light treatment of 135–170 J/cm2 delivered by a KTP:YAG laser coupled to dye unit. Two patients underwent a second PDT procedure due to new lesion formation. All patients were observed for a minimum of 6 months, and none was lost to follow‐up. RESULTS Photodynamic therapy was well tolerated with no photosensitivity reported. Despite all patients having failed surgery, full dose radiation and multiagent chemohormonal therapy, chest wall lesions healed with no scarring. Only 1 (9 cm) lesion took longer than 3 months to granulate over. The authors were able to evaluate all treatment sites, and complete response, defined as total lesion elimination, was noted in 89% of the lesions; reduction without regrowth occurred in 8% with no response in 3% of the lesions. CONCLUSIONS Despite having prior treatment and fragile tissues, low dose Photofrin‐induced PDT offers excellent clinical response with minimal morbidity. These results show that PDT should play an important role in the management of chest wall failure from breast carcinoma. Cancer 2001;91:1–8. © 2001 American Cancer Society.