Surgical ablation for oncological disease of the lateral skull base can result in extensive defects, with exposed bone and dura. Inadequate coverage can result in meningitis, osteomyelitis, or delay in adjuvant therapy. Successful reconstruction requires well-vascularized soft tissue and often a large cutaneous component. This study evaluates the role of free tissue transfer in reconstruction of lateral skull base defects. This study is a retrospective review of all patients undergoing lateral skull base resection for oncological disease and immediate reconstruction from 1993 through 1997. There were 18 patients with a mean age of 57 years. The temporal bone was resected in 50% of patients. All defects were reconstructed with free tissue transfers from the following donor sites: rectus abdominis (N = 14), latissimus dorsi (N = 2), anterolateral thigh (N = 1), and lateral arm (N = 1). A cutaneous skin island was employed in all patients. Free flap survival was 100%. Flap-related complications occurred in 33% of patients but did not delay the onset of adjuvant therapy. Vein grafts were not required to lengthen the vascular pedicle. Two patients required split-thickness skin grafts because of inadequate size of the skin island. Four patients underwent flap revision for contour deformity a mean of 4 months postoperatively. Free tissue transfer is a highly reliable method of reconstructing lateral skull base defects in a single stage. Careful flap selection and design can minimize the need for skin and vein grafts. The rectus abdominis donor site is preferred because of its location, large skin island, and excellent vascular pedicle.