This study assessed the anti-tumor activity and tolerability of gefitinib (IRESSA, ZD 1839) in a series of patients with previously treated advanced non-small cell lung cancer (NSCLC) seen at Charleston Area Medical Center in Charleston, W.Va. All patients were required to have proven advanced or metastatic NSCLC, along with meeting other study criteria. In 41 patients, the partial response rate was 7%, and 10% of patients achieved stable disease. Symptom improvement (dyspnea, anorexia) was reported in 44%. Mean survival for the entire group was 6.7 months (10.3 months for females, 3.7 months for males), with a 6-month survival rate of 33%. Adverse events were generally mild (grade I or II) and reversible and consisted mostly of diarrhea, rash, and anorexia. Although the major response rate was low, gefitinib (IRESSA, ZD 1839) demonstrated clinically meaningful anti-tumor activity with significant improvement in symptoms in this heavily pretreated group of patients with advanced NSCLC.