<p class="p1">Topical wound oxygen therapy (TWO) is widely used in North America and Europe. We initiated a clinical trial in 2010 to introduce this therapy into Japan; this involved six patients with chronic ulcers who underwent TWO. Pre- and post-treatment transcutaneous oxygen tension (TcPO2) values were evaluated at the periwound area. All cases showed increased TcPO2 values after TWO. In four cases, the size of the wound was reduced following treatment and there was formation of healthy granulation tissue. Wounds were completely closed by skin grafting in three of these four cases and healed spontaneously in one case.</p>n<p class="p1">One of the cases is presented in detail here.</p>n<p> </p>