Background: Despite advances in diagnosis and treatment bone infections remain a clinical challenge for the reconstructive surgeon. We present our experience with the V.A.C.Instill® therapy in patients with subacute or chronic bone infections in combination with a microsurgical flap reconstruction. Patients and methods: Six patients with subacute or chronic osteomyelitis were treated with the V.A.C.Instill® therapy. Five patients presented with an osteomyelitis of the lower extremity whereas one was located at the upper extremity. In all patients V.A.C.Instill® therapy was started directly after the first radical surgical bone and soft tissue debridement and was continued until surgical reconstruction was possible. Three patients receiv ed a free latissimus dorsi muscle flap whereof two were applied in combination with an autologous venous bypass. One defect was reconstructed by the use of a medial gastrocnemius muscle flap, one defect was covered with a combined free latissimus-dorsi- and serratus-anterior-muscle flap and one patient received a combined free groin and iliac crest flap. Results: V.A.C.Instill® therapy was tolerated well in all patients. After initiation of V.A.C.Instill® therapy tissue biopsies and superficial swabs were collected during the following dressing changes and surgical procedures. All bacterial cultures after initiation of V.A.C.Instill® therapy were sterile. After surgical reconstruction in all patients stable wound coverage with no signs of recurrence of osteomyelitis was achieved. Conclusions: In severe chronic osteomyelitis often complex microsurgical reconstructions are necessary to cure the infection and achieve stable defect coverage. V.A.C. Instill® therapy is a safe and easy to apply procedure to treat chronic osteomyelitis supportively besides a radical surgical debridement, microsurgical flap reconstruction and an adequate long-term antibiotic therapy. However prospective long-term studies are necessary to demonstrate a clear benefit of this procedure in terms of recurrence of osteomyelitis and predominance of the procedure especially in contrast to negative pressure therapy alone.