The purpose of this study is to evaluate if hyperbaric oxygen therapy heels more foot ulcers as compared to placebo in patients with diabetes mellitus and chronic foot ulcers.

Inclusion Criteria:

• diabetes mellitus,
• foot ulcer with duration > 3 months,
• treatment at Diabetes foot clinic for > 2 months,
• vascular surgical intervention had not been recommended for the affected lower limb.

Exclusion Criteria:

• severe obstructive pulmonary disease,
• malignancy and untreated thyrotoxicosis),
• current drug or alcohol misuse,
• vascular surgery in the lower limbs within the last two months,
• participation in another study or suspected poor compliance.