Forty-five patients receiving at least 5 sessions of hyperbaric oxygenation treatment were studied. Mean values of pulse rate were calculated during the different regimes of the session, as well as mean values of blood pressure before and after each treatment in order to assess the influence of hyperbaric oxygenation upon these parameters. With the hyperbaric oxygenation dosages employed in the group of patients studied, the variations of these parameters are not statistically significant. However, the behavior observed corresponds directly with the pressures used.