OBJECTIVE: Fluorescence biomodulation (FB), a form of photobiomodulation (PBM) that is also known as low energy level light (LELL), has become an increasingly used clinical tool to induce wound healing in wounds that remain recalcitrant to treatment. In a real-life clinical setting, the aim of the EUREKA (EvalUation of Real-lifE use of Klox biophotonic system in chronic wound mAnagement) study was to confirm the efficacy and safety of LumiHeal, a system based on FB, in the treatment of chronic wounds such as venous leg ulcers (VLUs), diabetic foot ulcers (DFUs) and pressure ulcers (PUs). The effects of this FB system on the modulation of wound healing in chronic ulcers through FB induction were previously examined in an interim analysis of this study. METHOD: A multicenter, prospective, observational, uncontrolled trial in 12 clinical sites in Italy. The wound was cleansed with saline and a 2mm thick layer of a chromophore gel was applied to the affected area in a biweekly regimen. The area was then illuminated with the LED activator for five minutes at a distance of 5cm. Treatment was used in combination with standard of care specific to each type of chronic wound (VLU, DFU, PU). Wound area evaluation was assessed using the Silhouette Imaging System and quality of life (QoL) with the Cardiff Wound Impact Schedule (CWIS). A seven-point evaluation of the clinicans' view was also examined. RESULTS: We enrolled 100 subjects, with the final analysis including 99 patients/ulcers consisting of 52 VLUs, 32 DFUs and 15 PUs. Total wound closure at the end of the study was achieved in 47 patients by aetiology: 26 VLUs (50% of VLUs); 16 DFUs (50% of DFUs); and five PUs (33.3% of PUs). The mean wound area regression at last study assessment was significant for VLUs (41.0%; p<0.001) and DFUs (52.4%; p<0.001). After four weeks of treatment, it was possible to significantly predict if the ulcer would respond (defined as a decrease of wound size) to the study treatment. Adherence was high (95.2%) and no related serious adverse events were reported during the study. QoL significantly improved, with an increase of 15.4% of the total score, using the CWIS (p<0.001). CONCLUSION: The study confirmed a positive efficacy profile of the FB system in inducing the wound healing process in three different types of hard-to-heal chronic wounds. The treatment was shown to be safe and well tolerated by the patients, with a significant improvement in patient QoL. This approach offers an effective modality for the treatment of hard-to-heal chronic ulcers.