Objective. To evaluate the short-duration hyperbaric oxygen therapy (HBOT) can improve HbA1c levels, leukocyte count, and serum creatinine levels in patients with diabetic foot ulcer (DFU) Wagner 3-4. Methods. Blood samples from all DFU patients at Sanglah General Hospital, Denpasar, were taken for HbA1c, leukocyte, and serum creatinine test before debridement procedure, and the patients were then grouped into either standard therapy or standard therapy with HBOT for 10 sessions (combination therapy). At the end of therapy, all blood tests were resumed. Results. Each group consisted of 15 patients. Results of laboratory analysis before and after treatment were significant regarding decrease of HbA1c levels in standard therapy (10.98 ± 2.37 % to 9.70 ± 2.46 %; p = 0.006), HbA1c levels in combination therapy (9.42 ± 1.96 % to 7.07 ± 1.16 %; p < 0.001), and leukocyte count in combination therapy (13.97 ± 6.24 x 103 cells/μL to 8.84 ± 2.88 x 103 cells/μL; p = 0.009). The HbA1c levels at the end of therapy were significantly different between groups (p = 0.001). Serum creatinine level was decreased only in combination therapy but it was not significant. The effect size of all variables was larger in the combination therapy, but it was not significant (p > 0.05). Conclusion. The use of short-duration HBOT on DFU reduces HbA1c levels, leukocyte count, and serum creatinine levels better than standard therapy alone. This protocol would save time and effort in future HBOT implementation.