Hansen's disease is a chronic infection caused by . Current therapy for this disease is with the WHO recommended Multi Drug Therapy (MDT) with DDS, rifampicin and clofazimine. Hyper Baric Oxygen Therapy (HBOT) has been used to treat many medical conditions including infections with a great deal of success. It's efficacy on various species of mycobacteria and other bacteria have been studied in vitro and in vivo and it is found to be an effective antimicrobial agent under specified conditions. HBOT has been used to treat Hansen's disease, including drug resistant lepromatous leprosy cases with good results. However there is a paucity of literature on this form of therapy. We have treated twenty cases of Hansen's disease with HBOT prior to exhibiting MDT as per the WHO schedule. There has been a marked regression in skin signs especially decrease in erythema and flattening of raised lesions. This correlated well with the histopathological picture which showed a reduction in the inflammatory exudate.