In the phase III TROG 05.01 trial, 310 patients with resected high-risk cutaneous squamous cell carcinoma of the head and neck received either chemoradiotherapy with carboplatin (area under the curve 2) or radiotherapy alone, in the adjuvant setting; 89% versus 88% of patients were free of locoregional relapse at 2 years, and the respective rates were 87% and 83% at 5 years (HR 0.84, 95% CI 0.46–1.55; P = 0.58). Similarly, no statistically significant differences in disease-free survival or overall survival were reported. Thus, postoperative radiation therapy is highly efficacious in this population and incorporation of carboplatin to postoperative treatment, although mostly well tolerated, provides no additional benefit.