Wound healing is actually a complex, precisely coordinated interaction between inflammatory cells and mediators, establishing significant overlap between the phases of wound healing. Chronic wounds are defined as wounds that do not follow the well-defined stepwise process of physiologic healing. The true incidence and economic impact of chronic wounds are difficult to assess because of the wide range of causative diseases and available treatment options. Despite multiple simultaneous and sequential therapeutic approaches, chronic wounds are highly resistant to treatment and are often indolent or even slowly progressive. Hyperbaric oxygen therapy (HBOT) has been explored as a treatment modality for chronic wounds because of its potential to promote healing and reduce bioburden in the wound bed. Multiple potential beneficial effects for wound healing have been demonstrated in various laboratory studies and experimental animal models. In this manuscript, HBOT, its mechanism of action, adverse effects and usage in diabetic and nondiabetic chronic wounds have been reviewed.