BACKGROUND : Daylight photodynamic therapy (dl-PDT) is an effective and almost painless treatment for patients with actinic keratoses (AKs) but carries important limitations due to seasonal conditions. PDT with Protoporphyrin IX (PPIX) peaks adjusted wavelengths might overcome these shortcomings. The aim of this study was to determine safety and efficacy of ALA-PDT with a new irradiation procedure. METHODS : Patients with AKs on the head received ALA-PDT with a new irradiation device. Emitted wavelengths are adjusted to PPIX absorption peaks (457 nm, 523 nm, 593 nm, 631 nm; 20.000 lx). PDT protocol was adapted for both 1 h of incubation and irradiation time. Outcome was assessed by AK area and severity index (AKASI) and lesion count (LC) prior to and 3 months after treatment. Safety was monitored by blood pressure and pulse measurements throughout treatment. Pain was determined by use of a visual analog scale (VAS). RESULTS : Overall, 39 patients were included and showed a significant AKASI reduction (P < 0.0001) 3 months after PDT (mean AKASI of 2 ± 1.6) compared to baseline (5.2 ± 1.9). Mean reduction rate was 63.7% ±24.2%, accordingly. Eight patients (20.5%) achieved AKASI 100, eleven (28.2%) AKASI 75 and thirty (76.9%) AKASI 50, respectively. There were no significant changes in blood pressure and pulse throughout treatment. Median VAS for pain during irradiation was 0 (0-1), 1 (0-1) and 0 (0-1) at the beginning, in the meantime and at the end, respectively. CONCLUSIONS : ALA-PDT with a new irradiation procedure is a safe, effective and almost painless treatment option for patients with AKs on the head.