Hyperbaric oxygen therapy appears to be a promising adjunctive treatment for a variety of equine disorders, including laminitis and other ischemic injuries. Hyperbaric oxygen (HBO) is a high-dose oxygen inhalation therapy that is achieved by having the patient breathe 100% oxygen inside a pressurized hyperbaric chamber. The delivery of oxygen to the tissues is through respiration because there is insufficient absorption of oxygen through the skin. The benefits of HBO are derived from both the physiologic and pharmacologic effects of high-dose oxygen. HBO is based on two physical factors related to the hyperbaric environment: mechanical effects of pressure and increased oxygenation of tissues. The use of HBO by veterinary medical hospitals is in its infancy. Our clinic has currently treated more than 250 patients in our HBO chamber. Patients included pregnant animals as well as neonatal foals, with no adverse effects noted. Patients have been pressurized from 1.5 to 3 ATA (ATM absolute) ranging from 60 to 90 minutes at treatment pressure (depth). Hagyard Equine Medical Institute has used HBO as adjunctive therapy for fungal disease (fungal pneumonia); thermal burns, carbon monoxide, smoke inhalation; closed head injuries; ileus; central nervous system edema/perinatal asphyxia; peripheral neuropathies; sports injuries (exertional rhabdomyolysis); cellulitis; compartment syndrome; and ischemic injuries (laminitis). In carefully selected patients, the addition of HBO therapy to standard measures may improve clinical outcomes. Further research is needed in the field of equine HBO medicine.