In patients with locally or regionally advanced head and neck carcinomas, postoperative radiotherapy has historically been the adjuvant therapy applied for patients with prognostically worrisome pathologic features. Any improvement in therapeutic index achieved by adding cytotoxic agents to postoperative radiotherapy remained controversial. However, two recent randomized trials, conducted in parallel in Europe and the United States, produced level I evidence regarding improved efficacy in this setting for the concurrent administration of chemotherapy and radiotherapy. High-dose cisplatin and irradiation can now be considered the standard therapeutic approach for resected poor-risk disease. The presence of positive margins and/or nodal extracapsular spread in the surgical specimens are the subgroups that appear to benefit in the most significant way from the addition of chemotherapy to radiation. Many questions regarding the optimization of adjuvant treatments still remain unanswered, especially with respect to improvement of patient compliance, integration of novel drugs targeting both locoregional and systemic control, and modulation of treatment intensity according to risk levels.