Background/Aim. Hyperbaric oxygenation (HBO) is a medical treatment of a patient with 100% oxygen inspiration under the pressure higher than atmospheric in a special unit designed to let the whole patient's body rest in a chamber. The aim of the study was to determine the effect of the application of HBO treatment on the patient's lower extremities with chonic inoperabile occlusive disease by measning the parameters of perfusion scintigraphy (perfusion reserve, relative perfusion). Methods. This investigation included 22 patients (19 males and 3 famales). Following clinical assessment of lower extremities condition according to the skin appearance and its adnexa, claudication distance was performed. Clinical condition was graded by the use of 5-point nominal scale. In all of the patients 99mTctetraphosmine lower extremities scintigraphy was done ten days prior to the treatment start and ten days after the treatment with HBO. Lower legs were imaged from the posterior view. Prior to imaging the patients were obligatory lying approximately half an hour. Results. In 18 (86%) of the patients there was an improvement manifested as better subjective condition and better skin and its adnexa appearance. Following HBO treatment there was a statistically significant change in collecting the radiopharmac at rest. This finding indicates an increased viability of muscles as well as an increased perfusion reserve. Perfusion reserve mean values increased from 39.99 to 50.86%, and from 38.46 to 49.33% for the right and the left lower leg, respectively. This parameter clearly indicates favorable effects of HBO treatment pertaining neoangiogenesis and, consequently, increased viability of the lower leg muscles. It was also obvious in visual analysis of the obtained images. Conclusion. The obtained results confirm that muscle perfusion measured by the parameters of perfusion scintigraphy using 99mTc-tetrophosmine (perfusion reserve, relative perfusion) in patients with inoperable occlusive disease of the lower leg arteries significantly increases after the application of HBO treatment.