Knowing that in hyperbaric-hyperoxic environment, the production of free oxygen radicals is increased, with the direct implications on cellular metabolism, our study follows the influence of the hyperbaric environment, a very complex organ that is exposed to directly to this environment. We used a group of 10 guinea pigs split into to lots (test and control lots). The test lot was exposed for consecutive days to an ambient pressure of 6 ATM for a period of 30 min. After 50 days both groups was given lethal doses of pentobarbital, afterwards skin was harvested and fixed into Bouin's fluid and formaline, than paraffin embedded. The slides stained with Haematoxylin-Eosin and trichromic Van Gieson. The epidermal fields examined by us revealed no significant variations of nuclear number, though the mean saturation of nuclei was significantly greater in test animals than in the control group, while the nuclear area fraction was higher in the control group. The melanin load of the epidermal cells was increased in the control animals. The presence of intraepidermal vacuoles was identified, their amount being almost double in test animals than in the control group.