Hyperbaric oxygen therapy (HBOT) delivers 100% inspired oxygen to individuals at 2.0 to 2.5 absolute atmospheres (ATA) of pressure for a typical total duration of 60-120 minutes during 1-2 daily sessions inside a hyperbaric chamber. During a course of up to 30 treatments, adequately perfused wounds with delayed healing associated with limited local tissue oxygenation are expected to improve in healing parameters based on the assumption that local hypoxia is contributing to their delayed healing. A wound must have sufficient circulation for the 100% inspired oxygen to increase local oxygen levels in its hypoxic periwound tissue to respond to HBOT. The wide variety of chronic wound etiologies, not all involving local hypoxia, coupled with wide variability in parameters for administering HBOT have contributed to uncertainty about HBOT efficacy in treating chronic wounds. Instead of asking, “Does chronic wound healing improve in response to HBOT?” perhaps the question should be, “How can one recognize which chronic wound(s) are likely to improve their healing in response to HBOT as an adjunct to recognized standard(s) of care?” This Evidence Corner describes 2 publications designed to clarify the question of HBOT efficacy. The first is a Cochrane review of HBOT effects on chronic wounds.1 The second is the only randomized clinical trial (RCT) of HBOT effects on venous insufficiency ulcers2 found by searching the MEDLINE, Google Scholar, and ClinicalTrials.gov databases from inception to November 8, 2015, for combined terms “hyperbaric oxygen and venous ulcer” while seeking evidence supporting the multinational intersociety collaboration updating the former Association for the Advancement of Wound Care Venous Ulcer Guideline, now called the International Consolidated Venous Ulcer Guideline.