The aim of this work was to identify clinical data indicative of the number of hyperbaric oxygen therapy HBO2 sessions that should be prescribed for adjuvant treatment of tissue injuries of differing severity. A total of 1730 cases of patients treated with HBO2 using an open protocol (without a predetermined number of sessions) was examined in this study. A retrospective study involving charts review was conducted. Severity had been previously determined for the treatment of acute (fasciitis, myositis, gangrene, contaminated/infected perineal or lower extremity traumatic injuries) or chronic (osteomyelitis, pressure sore, diabetic or ischemic ulcer) injuries. Only patients that met or exceeded the supposed effective minimal treatment doses (5 sessions for acute, 10 sessions for chronic injuries) were included in the present study. The data analysis included 1506 cases. These consisted of 1014 patients with acute injuries, who required 11 to 18 sessions (depending on injury severity), and 492 patients with chronic injuries, who required a greater (p < 0.001) number of sessions (approximately 30/patient, independent of injury severity). Global mortality was 79/1506 patients. D'Agostino Dias, Fontes, Poggetti, Birolini, , , , , (). Hyperbaric oxygen therapy: types of injury and number of sessions–a review of 1506 cases.¬†Undersea & hyperbaric medicine : journal of the Undersea and Hyperbaric Medical Society, Inc, ;35(1):53-60.¬†https://www.ncbi.nlm.nih.gov/pubmed/18351127