For safe and reliable skull base reconstruction combined with repair of cranial bone defects, we introduce the flap sandwich technique in this study. A titanium mesh is often used to repair structural cranial bone defects because it has less donor site morbidity and is easy to handle. However, titanium mesh has disadvantages of exposure and infection postoperatively. To improve surgical outcomes, we applied the flap sandwich technique to 3 cases of skull base reconstruction combined with cranial bone defect repair. Two anterior skull base defects and 1 middle skull base defect were included in this study. The subjects were all women, aged 30, 58, and 62 years. One patient had former multiple craniotomies and another patient had preoperative radiotherapy. The flap sandwich technique involves structural cranial bone reconstruction with a titanium mesh and soft tissue reconstruction with a chimeric anterolateral thigh free flap. First, the dead space between the repaired dura and the titanium mesh is filled with vastus lateralis muscle, and then structural reconstruction is performed with a titanium mesh. Finally, the titanium mesh is totally covered with the adiposal flap of the anterolateral thigh free flap. The muscle flap protects the dead space from infection, and the adiposal flap covers the titanium mesh to reduce mechanical stress on the covered skin and thus prevent the exposure of the titanium mesh through the scalp. By applying this technique, there was no intracranial infection or titanium mesh exposure in these 3 cases postoperatively, even though 2 patients had postoperative radiotherapy. Additionally, the adiposal flap could provide a soft and natural contour to the scalp and forehead region, and this gives patients a better facial appearance even though they have had skull base surgery.