Activation of the epidermal growth factor receptor (EGFR) has been linked to tumour proliferation, invasion, metastasis and angiogenesis in epithelial tumours. Inhibitors of the EGFR have emerged as promising anticancer agents and two main approaches have been developed, humanised monoclonal antibodies and tyrosine kinase inhibitors. This review discusses the current status of EGFR tyrosine kinase inhibitors (EGFR-TKIs) that have entered clinical development. EGFR-TKIs are generally well tolerated and can sometimes produce impressive tumour regression in patients with advanced non-small-cell lung cancer. However, highly predictive or surrogate markers of activity have not been identified and there remains a need for translational research in their future development.