BACKGROUND: Foot ulceration usually precedes more serious foot complications such as infection, gangrene or amputation. The risk of developing foot ulcers has been estimated to be higher in individuals with peripheral arterial disease, diabetes and kidney disease. OBJECTIVE: To evaluate the healing potential of CO2-enriched water in patients with foot ulceration. METHODS: This is a multi-centered; placebo controlled and randomized clinical trial. Patients will have at least 1 distal extremity ulcer and will be randomized to receive a treatment with bath therapy at 37ºC containing either 1,000-1200 ppm CO2-enriched tap water (the intervention), or non- carbonated tap water (the control group). The treatment will be carried out 3 times/week for 15 minutes per session for 4 months for a total of 48 treatments. At baseline and at the end of every treatment month, wound assessment, measurement of limb oxygenation, ankle brachial pressures as well as McGill pain questionnaire will be carried out. Blood will also be collected at baseline and at the end of every month of the treatment period (for a total of 5 collections) for the measurement of different biomarkers. BASELINE DATA: At baseline all 14 participants have at least one distal extremity ulcer and 93% (13/14) are diabetic. Although 6 of the participan`ts have peripheral arterial disease (left and/or right limb) as evidenced by an ankle brachial index (ABI) <0.9, another 5 exhibited non-compressible ankle arteries and 3 participants with left and right ABI of ≥ 0.9. Mean age of participants is 60.2 ± 1.7 and 64% (9/14) of the participants are undergoing hemodialysis for ESRD and 29% (4/14) are below knee amputees. CONCLUSIONS: The proposed clinical study will evaluatve the therapeutic potential, safety and efficacy of CO2 enriched water (produced by the Carbothera device) on treating foot ulcers.