Inhibition of the epidermal growth factor receptor is one of the most promising novel therapeutic strategies to be used in the treatment of patients with non-small cell lung cancer. A number of compounds that target the epidermal growth factor receptor are in an advanced stage of clinical development including both antibodies directed against the receptor and small molecule inhibitors of epidermal growth factor receptor tyrosine kinase activity. This drug profile focuses on the development of erlotinib, an orally available inhibitor of epidermal growth factor receptor tyrosine kinase. Results of clinical trials are reviewed, two trials of erlotinib in combination, one with paclitaxel and carboplatin, the other with gemcitabine and cisplatin, and the National Cancer Institute of Canada--Clinical Trials Group BR21, the first study to demonstrate a survival benefit for this class of compound in non-small cell lung cancer. The future role of erlotinib in the management of patients with non-small cell lung cancer is also discussed.