BACKGROUND: Unmet needs exist in actinic keratosis (AK) treatment. Daylight photodynamic therapy (DL-PDT) has shown good efficacy and safety results compared to conventional PDT (c-PDT) in a recent Phase III multi-centre randomised controlled trial in Australia among 100 subjects with AKs.\n\nOBJECTIVES: Demonstrate non-inferior efficacy and superior safety of DL-PDT compared to c-PDT in treating multiple mild and/or moderate facial/scalp AKs.\n\nMETHODS: Phase III, 12 week, multi-centre, randomised, investigator-blinded, controlled, intra-individual study conducted at different latitudes in Europe. AKs of adult subjects were treated once with methyl aminolevulinate (MAL) DL-PDT on one side of the face and MAL c-PDT contralaterally. Endpoints for DL-PDT concerned efficacy (non-inferiority regarding complete lesion response at week 12) and safety (superiority regarding subject's assessment of pain after treatment, on an 11-point numeric rating scale). Safety evaluation also included incidence of adverse events. Subject satisfaction was described using a questionnaire at baseline and last visit.\n\nRESULTS: At week 12, the total lesion complete response rate with DL-PDT was similar (non-inferior) to c-PDT (70% vs. 74%, respectively; 95% CI [-9.5; 2.4] in PP analysis, confirmed in ITT analysis). In addition, efficacy of DL-PDT was demonstrated regardless of weather conditions (sunny or cloudy). DL-PDT was nearly painless compared to c-PDT (0.7 vs. 4.4, respectively; P <0.001), better tolerated and resulted in higher subject satisfaction.\n\nCONCLUSION: DL-PDT in comparison with c-PDT was as effective, better tolerated and nearly painless with high patient satisfaction, and may be considered a treatment of choice to meet needs of patients with mild or moderate facial/scalp AKs.