Hydrogen sulfide inhalation injury can be life threatening. The toxic gas is produced, sometimes unexpectedly, from a wide variety of sources. Because its mechanism of toxicity is similar to that of cyanide, hydrogen sulfide poisoning is commonly treated with the nitrite component of the cyanide antidote kit. In this case report, hyperbaric oxygen was successfully used to treat hydrogen sulfide intoxication. Further evaluation of hyperbaric oxygen therapy as adjunctive treatment of hydrogen sulfide poisoning is recommended.