Cetuximab (C225, Erbitux, Merck, Darmstadt, Germany) is a human-mouse chimeric therapeutic monoclonal antibody (mAb) that competitively binds to the extracellular domain of the human epidermal growth-factor receptor (EGFR). It has been developed out of the murine antibody M225 "from bench to bedside" in less than two decades, and is the anti-EGFR mAb furthest ahead in clinical evaluation. In Europe, cetuximab is approved for the treatment of patients with EGFR-expressing, metastatic colorectal cancer after failure of treatment with irinotecan since 2004, and for the treatment of patients with locally advanced squamous cell cancer of the head and neck concomitant to radiotherapy since 2006. We here summarize the current role of cetuximab in the treatment of colorectal cancer, give an overview on the ongoing studies, address the most important controversies, and point out the chances and challenges for the future use of cetuximab in colorectal cancer and other human malignancies.