The addition of concurrent chemotherapy (CT) to standard radiotherapy (RT) for locoregional treatment has been established to improve overall survival in a variety of solid tumors. Among the many CT regimens evaluated in combination with RT in randomized controlled clinical trials and summarized in meta-analyses, platinum-containing regimens have consistently shown a survival benefit across tumor types. Cisplatin and carboplatin have been studied both as single agents and in combination with other cytotoxic drugs, concurrently with RT, but the optimal platinum-based regimen to be combined with RT continues to be explored with further investigation. In this article, the role of platinum-based CT as part of concurrent CT/RT will be discussed using 2 tumor sites in the aerodigestive tract as a paradigm: squamous-cell carcinomas of the head and neck and esophageal carcinomas. For each tumor type, we will review the state of the evidence and comment on the current state of practice and on future directions for clinical research in combined modality CT/RT.