This is a single-institution, open-label, non-randomized phase II trial of erlotinib administered concomitantly with radiation therapy following surgical resection of gross disease. A total of 45 patients with previously unirradiated, high-risk cutaneous SCC requiring post-operative radiotherapy will be enrolled to assess the primary endpoints of time to recurrence and disease free survival. Pretreatment biopsies will be required to confirm the histological diagnosis of SCC. Four to six weeks after surgical resection, patients will begin erlotinib (150 mg po qd) beginning the first day of radiotherapy. Patients will receive 5040 cGy beginning on day 1 of therapy in standard fractionations. Patients will be followed to evaluate for toxicity based on NCI common toxicity criteria (v3.0). Patients will be followed on protocol for a minimum of 2 years with regularly scheduled CT scans, clinical evaluations, and laboratory work. Patients with residual or recurrent cancer will be taken off protocol for salvage therapy.