Surgical treatment is required for patients with chronic or refractory radiation ulcers. For reconstruction, distal pedicled flaps are preferable because the tissue surrounding the ulcer is often damaged by radiotherapy. We treated five patients with radiation ulcers using microsurgery. We herein summarize the surgical techniques and outcomes, and analyzed these data retrospectively. Two ulcers were considered to be due to early skin reactions, and the other three were thought to be late skin reactions because they had been treated by radiotherapy over 10 years prior to presentation. For one patient, a supercharged rectus abdominis musculocutaneous flap was used, and for the other four, free flaps were used. In two patients, reanastomosis was required because of venous thrombosis. In two patients, we used a vein graft. All flaps were successfully transferred without necrosis. In conclusion, reconstruction with vascular anastomosis is useful for surgical treatment of radiation ulcers when a pedicled flap cannot be used and the recipient vessels are suitable for anastomosis.