The effect of hyperbaric oxygen therapy (HBO) on survival of the distal skin paddle with early pedicle division was studied in a rat tubed pedicle flap model. In part 1, tubed pedicle skin flaps were created on the backs of 14 rats. The pedicle of each skin flap was divided at intervals of 3, 4, 5, and 7 days, and the survival area of each distal skin paddle was measured 5 days after each pedicle was divided. The results showed that the percentages of survival were 0%, 29.9%, 89.9%, and 100% at 3, 4, 5, and 7 days, respectively. In part 2, the tube flaps were created on the backs of 28 rats. The tubed pedicles were divided 4 days after creation. In the experimental group 1 (n = 9), the rats received HBO treatment at 2 atm of pressure twice daily for 3 consecutive days before pedicle division. In the experimental group 2 (n = 9), the rats received HBO treatment after pedicle division twice daily for 3 consecutive days. In the control group (n = 10), the rats received no HBO treatment. The results showed that the mean survival area of the distal skin paddle at 5 days after pedicle division for the groups treated with HBO before and after pedicle division was 6.31 +/- 2.69 cm2 (69.19%) and 6.12 +/- 1.52 cm2 (71.22%), respectively. These survival rates were of statistical significance as compared with the survival rates in the control group of 2.70 +/- 1.89 cm2 (27.9%). These results demonstrate that the administration of HBO therapy to the animal with a tubed pedicle flap can increase flap survival with early division of the tubed pedicle.