Surgical resection is the first-choice therapy for extramammary Paget's disease, but extensive resection is highly invasive and non-surgical treatments are sometimes preferred. Although photodynamic therapy (PDT) has been used for extramammary Paget's disease for some time, recurrence and residual tumour cells are common. In the present study, five patients with extramammary Paget's disease with a total of eight lesions first underwent carbon dioxide (CO2) laser abrasion, followed by 3 h of occlusive application of aminolaevulinic acid (ALA) and then 100 J/cm2 irradiation with a 630-nm excimer dye laser. This combination treatment regime was repeated every 2 weeks for a total of 3 times. Group 1 comprised two patients (five lesions) who received CO2 laser and ALA-PDT only. Group 2 comprised three patients (three lesions) who received CO2 laser and ALA-PDT for residual tumour cells following surgery. Follow-up examinations showed that seven lesions in five patients had not recurred after 12 months, suggesting the efficacy of the present method.