OBJECTIVE: To evaluate the effect of Vacuum-Assisted Closure (V.A.C.) therapy in stage 3 or 4 pressure ulcers refractory to traditional saline wet gauze dressing. METHOD: Ten patients who had stage 3 or 4 pressure ulcers which were failed to heal with saline wet gauze dressing over 4 weeks were investigated. We treated these subjects with V.A.C. therapy. The length, width and depth of pressure ulcers were evaluated every week for 3 weeks. Soft tissue biopsy from pressure ulcer was taken before starting V.A.C. therapy and after the scheduled therapy was done. RESULTS: The sizes of length, width and depth in pressure ulcer were significantly decreased after one week of V.A.C. application. And then healthy granulation tissue was formed. The length, width and depth of the pressure ulcer were decreased of 40.2%, 42.7% and 79.8% of their original size. Soft tissue biopsy in pressure ulcers was taken in 4 cases, the number and size of capillaries were more increased and inflammatory cells were decreased. CONCLUSION: V.A.C. therapy promoted wound healing and revealed favorable histological changes in pressure ulcers refractory to traditional dressing. We suggest that V.A.C. therapy can be used for the effective management of pressure ulcer.