One of the main causes of amputations in patients with Diabetes Mellitus patients is a chronic diabetic foot ulcer. The authors present a clinical case and discussion of a successful use of Granulocyte-Macrophages Colony Stimulating Factor (GM-CSF) treatment for the promotion of healing of a chronic diabetic foot ulcer. A 65 year-old woman was admitted to the Diabetes Center with complaints of a deep non-healing chronic foot ulcer for the last 18 months. At the examination a 5 cm ulcer on the plantar surface of the right foot was revealed. The patient had a 15-year history of Diabetes Mellitus type 2, complicated by neuropathy (peripheral and autonomic), retinopathy, nephropathy and Charcot joints in both legs and the right 4th toe had been amputation. She also had a history of heart failure. Healing of the ulcer could not be achieved with prior administered treatment. The decision was made to use GM-CSF treatment option in the area of the ulcer. Patient received local intradermal injections of GM-CSF (400 mcg twice a week) into the ulcerated foot for the duration of two months. The ulcer healed completely after one year of treatment with GM-CSF. Osteomyelitis was ruled out by scintigraphy. The patient did not develop any clinical side-effects or peripheral blood cell count abnormalities to the treatment. GM-CSF is a safe and effective treatment for chronic non-healing diabetic foot ulcers.