Recently, the number of patients with peripheral artery disease (PAD), including those with chronic limb-threatening ischemia (CLTI), has increased because of the increasing number of diabetic or dialysis patients worldwide. Revascularization is an important therapy for patients with CLTI. However, we sometimes experience refractory cases with insufficient peripheral circulation or microcirculation after revascularization. In this situation, additional therapy can be administered, such as low-density lipoprotein apheresis, high-pressure oxygen therapy, and spinal cord stimulation. However, they are not effective in some cases. Some reports have also indicated that transdermal isosorbide dinitrate patch (ISDN-P) is a useful therapy for PAD. As the efficacy of ISDN-P for patients with CLTI is not well-known, we examined it in this study. We assessed the skin perfusion pressure (SPP) after affixing an ISDN-P on the foot, because SPP measurement has proved useful in the assessment of PAD and is a good indicator of wound healing potential. The SPP (dorsal and plantar aspects) after ISDN-P application on the foot of healthy volunteers increased (n = 8; mean ± SD, 12.6 ± 7.9 [P = .12], and 21.2 ± 7.7 mm Hg [P < .05], respectively), as did SPP of patients with CLTI (n = 10; mean ± SD, 19.8 ± 2.5 [P < .01], and 14.1 ± 5.9 mm Hg [P < .05], respectively). All the patients who received an ISDN-P on the foot had no major complication, and no significant change in blood pressure. In conclusion, the ISDN-P is one of the effective and safe therapies for patients with CLTI.