Acute wounds will generally heal independently of any interventions, whereas chronic wounds are chronic for a reason and are unlikely to successfully heal without intervention. In the treatment of venous leg ulcers, the gold standard will always be compression therapy. However, many wounds still do not heal despite best practice. Therefore, the use of adjunct therapies alongside standard care become the priority for healing. This article describes a small evaluation, involving 17 patients with chronic venous leg ulcers, that set out to determine the effect of a topical oxygen therapy on wound size. The therapy comprises a canister that sprays pure haemoglobin in a water solution into the wound. The haemoglobin spray needs to be used at least once every 3 days, and no training is required on its use. Results showed the device helped promote wound healing in 14 out of 17 wounds treated for more than 2 weeks. These patients had previously been shown to be non-healing during a 4-week run-in period where they received standard care, including compression therapy.