Photodynamic therapy (PDT) has been reported to be useful in treating non-melanoma skin cancers and a variety of benign skin conditions including psoriasis. However, only two reports of palmoplantar pustular psoriasis (PPP) treated with PDT have been reported. We treated three intractable cases of PPP with PDT, using 20% 5-aminolaevulinic acid and a 630+/-50 nm light-emitting diode device. The power density was 30 mW/cm2 and the fluence was 15 J/cm2. After treatment, all cases showed mild to marked improvement. Topical PDT may be an alternative therapy in the treatment of PPP, but further study is necessary to confirm the effectiveness of topical PDT in PPP.