In this prospective pilot study we investigate whether the photodynamic therapy (PDT) is effective for treatment of lentigo maligna. 10-15 patients with a histologically confirmed lentigo maligna are included in the trial. The study course is as follows: During the first visit in the clinic, the suspected LM lesion is examined clinically under Wood's lamp and imaged with a HIS camera. Elicited margins from both methods are marked on a transparent sheet and the treatment area is photographed. A biopsy is taken from the darkest-colored part of LM to confirm diagnosis and to rule out invasion. Next, the patients receive PDT treatment three times with 2 weeks' intervals. Before applying the Ameluz® light sensitizer gel the skin of treatment area is prepared with fractional ablative CO2-laser to enhance absorption. After light sensitizer absorption the LM lesion is illuminated with artificial red light (Aktilite CL128 lamp) using a light dose of 90 J/cm2. Finally 4 weeks after the last PDT treatment LM is excised surgically using 5 mm margins. The efficacy of PDT is assessed after surgical excision with histopathological examination and immunohistochemical staining (MART, Mel-5 and MITF stains). The final result of the treatment is controlled 6 months after the surgical excision.