Since Endre Mester's initial reports on the application of low-incident energy laser radiation for the successful therapy of treatment-resistant torpid crural ulcers, many other reports have appeared in the literature on the success of laser therapy in many aspects of wound healing. The semiconductor diode laser, helium-neon (HeNe) laser, neodymium yttrium aluminium garnet (Nd:YAG) laser, carbon dioxide (CO₂) laser and ruby laser have appeared in various reports as having a good effect on abnormally-healing wounds. We report in this paper on a late-middle-aged male patient with a therapy-resistant lower extremity ulcer, diagnosed as diabetic arteriosclerosis obliterans. Despite two months as an inpatient and a variety of therapeutic modalities, including infrared diode laser (GaAlAs, 60 mW c/w, power density of approximately 3 W/cm²), the ulcer failed to heal. HeNe LLLT was then started (8.5 mW c/w, scanned mode, power density 27 W/cm²), twice per day, 10 minutes per session. After one month, considerable improvement was seen in both healing and pain removal, and the ulcer had healed completely after five months, with complete pain removal. It is suggested that, for open wounds requiring direct irradiation to the wound bed, the HeNe laser at 632.8 nm is most effective, applied in the noncontact scanning mode.