To determine the effects of hyperbaric oxygen (HBO) therapy on short-term complications of complex war wounds to the upper and lower extremities in patients who were and those who were not treated according to North Atlantic Treaty Organization (NATO) emergency war surgery recommendations. We retrospectively analyzed data of 388 male patients undergoing reconstructive surgery for Gustilo type III A, B, and C war wounds to the extremities at the Department of Reconstructive Surgery, Split University Hospital Center, between 1991 and 1995. The occurrence of main wound complications (deep infection, osteomyelitis, skin grafts lyses, and flap necrosis) during hospitalization and time from wounding to granulation formation were analyzed with respect to the use of HBO therapy as a risk factor. Odds ratio (OR) with 95% confidence intervals (CI) was calculated for the occurrence of wound complications with respect to HBO therapy and adjusted for NATO surgical strategy by logistic regression. Of 388 patients, 310 (80%) were initially treated according to the NATO surgical strategy and 99 (25%) received HBO therapy. Deep soft-tissue infection developed in 196 (68%) patients who did not receive HBO therapy and in 35 (35%) who received it (P<0.001, xi(2) test). Osteomyelitis developed in 214 (74%) patients who did not receive HBO therapy and in 62 (63%) who received it (P=0.030). Skin graft lysis occurred in 151 (52%) patients who did not receive HBO therapy and in 23 (23%) who received it (P<0.001). Flap necrosis occurred in 147 (51%) patients who did not receive HBO therapy and in 15 (15%) who received it (P<0.001). Median time to granulation formation was 9 (5-57) days in patients who received HBO therapy, and 12 (1-12) days in those who did not (P<0.001, Mann-Whitney test). These results were consistent over the groups of patients stratified according to the wound severity and remained unaltered after the adjustment for NATO surgical strategy. The effect of HBO therapy was greater in non-NATO than in NATO treated patients in case of deep soft-tissue infection (OR, 10.7 vs OR, 3.8; P=0.031 for interaction). HBO therapy reduced the frequency of wound complications in patients with Gustilo type III wounds and shortened the time to granulation formation. HBO therapy was more effective in non-NATO than in NATO treated patients for the prevention of deep soft-tissue infection but not flap necrosis.