This report deals mainly with the role of hyperbaric oxygen therapy (HBO) in the treatment of gases intoxication and several other tissue poisons. There are reports of the use of HBO in cases of gas intoxication including ammonia, chlorine gas, cyanide, hydrogen sulfide (H2S), carbon monoxide(CO), benzene etc; in situations like this one cannot have controlled studies. In a critical case HBO should be considered as a supplement to conventional methods. 1989 Marzella have investigated the effect of HBO on liver damage caused by toxins. HBO was found to have a marked effect on toxic liver damage caused by toxins, reduced edema and increasing oxygen pressure in tissues or organs.