This is a phase II, multicenter, target enrollment of 250 evaluable patients, open-label study of cetuximab in patients with refractory, metastatic colorectal carcinoma. Based on prior studies, we predict that 70 to 75% of patients will be EGFR-positive. Patients must have documented failure after receiving either at least two chemotherapy regimens for metastatic disease or adjuvant therapy plus one chemotherapy regimen for metastatic disease provided that the patient progressed within 6 months of completing adjuvant therapy. Prior chemotherapy must have included irinotecan, oxaliplatin, and a fluoropyrimidine.