The management of critical bone defects in patients with fracture-related infections presents a significant challenge. In this chapter, we discuss how bone flaps differ from other alternatives for infected bone defects, which patients are most benefited by them (and which are better off with other techniques), which bone flaps are most frequently used in the context of fracture-related infection, and what their possible complications are. Bone flaps (also referred to as vascularized bone grafts) have an intrinsic blood supply. This blood supply plays a crucial role in facilitating healing by enabling antibiotics to reach the site of injury (higher resistance to infection), promoting bone healing (higher union rates), allowing retention of the transplanted bone’s biomechanical properties (hypertrophy, minimal resorption) and the incorporation of other tissue components (composite flaps). The trade-offs are donor-site morbidity, longer surgical times, and a higher technical demand. Due to its geometry and versatility, the fibula flap is the most commonly used flap for treating long-bone defects. To avoid stress fractures, limiting weight-bearing and adequate bone fixation are essential. The medial femoral condyle flap is becoming increasingly popular and is an excellent option for small defects because it offers pliability and minimal donor-site complications. Other flaps, such as the iliac crest flap, are usually reserved for situations where the fibula, medial femoral condyle, and/or distal radius flaps are unavailable.