Agents targeting the epidermal growth factor receptor (EGFR) pathway hold particular promise for the treatment of patients with advanced disease, for whom standard chemotherapy is generally palliative. Expression of EGFR on numerous types of solid tumors, and the association of EGFR activation with tumorigenic processes including proliferation, anti-apoptosis and metastatic spread, make this pathway a particularly compelling target for rational drug design. The two classes of anti-EGFR agents in late-stage clinical testing include antibodies directed toward the extracellular EGFR domain (cetuximab, panitumumab) and small molecule tyrosine kinase inhibitors (gefitinib, erlotinib), which inactivate the receptor enzyme activity. However, important issues remain to be addressed. These include the development of appropriate predictive markers for response, such as improved tests for EGFR activity, correlation of rash with response and potential pharmacogenomic approaches; the sequencing and combination of these agents with chemotherapy and irradiation; and the possible role of these agents in the treatment of patients with earlier stage disease.