Background and Objectives: Nonmelanomatous skin tumours are the most frequent tumours in the white population and mainly caused by cumulative exposure to ultraviolet B radiation. On account of this origination about 80% of all nonmelanomatous skin tumours are located on the arms or the head and neck. Standard treatment for most tumours is surgical resection, with often only moderate cosmetic outcome. Study Design/Materials and Methods: In a prospective clinical trial the effect of photodynamic therapy on primary nonmelanomatous skin tumours of the head and neck (basal cell cancer, squamous cell cancer) was tested. In this study Foscan (meta-Tetrahydroxyphenylchlorin/mTHPC), a systemic photosensitizer of the second generation, was applied. Patients were injected 0.15 mg/kg or 0.10 mg/kg Foscan intravenously 96 hours prior to laser light exposure. Light was delivered via fibres by an argon-dye laser at 652 nm, 100 mW/cm 2 and a light dose of 5-20 J/cm 2 . Results: Eighteen patients with a total of 97 nonmelanomatous skin tumours and a mean follow up of 15 months (ranging 3-24 months) were treated. Within several days tumour necrosis appeared followed by wound healing within 4-8 weeks, leaving only minor scars behind. Ninety tumours (92.7%) showed a complete response with an excellent cosmetic outcome and only seven tumours responded by partial success due to low light dosage. The cosmetic outcome was very good and the therapy was supported by a high degree of patient satisfaction. Conclusion: By choosing the correct drug and light dosage, a selective tumour necrosis can be obtained. Photodynamic therapy (PDT) using Foscan seems to be a promising new and safe treatment modality for the treatment of primary nonmelanomatous skin tumours of the head and neck that can substitute surgical therapy, offering an even better cosmetic outcome.