Our objective was to evaluate gefitinib (IRESSA), an epidermal growth factor receptor tyrosine kinase inhibitor, versus docetaxel as second-line monotherapy for advanced non-small-cell lung cancer (NSCLC). SIGN (Second-line Indication of Gefitinib in NSCLC; code 1839IL/0503) was a multicenter, randomized, parallel-group, open-label, phase II trial that investigated oral gefitinib (250 mg/day) or i.v. docetaxel (75 mg/m2 every 3 weeks) in patients with advanced NSCLC who had previously received one chemotherapy regimen. The primary objective was assessment of symptom improvement (using the FACT-L Lung Cancer Subscale). Secondary objectives included quality of life (FACT-L total score), response rate (using RECIST), overall survival and safety. This trial recruited 141 patients (68 to gefitinib and 73 to docetaxel) who received treatment for a median duration of 3.0 (gefitinib) and 2.8 (docetaxel) months. Similar efficacy was observed with gefitinib and docetaxel, 36.8 and 26.0% symptom improvement rates, 33.8 and 26.0% quality-of-life improvement rates, 13.2 and 13.7% objective response rates, and 7.5 and 7.1 months median overall survival, respectively. Fewer drug-related adverse events were observed with gefitinib compared with docetaxel (all grades: 51.5 versus 78.9%; Common Toxicity Criteria grade 3/4: 8.8 versus 25.4%). There were no withdrawals or deaths due to drug-related adverse events with gefitinib, while three patients withdrew and three died due to adverse events in the docetaxel group that were possibly drug related. We conclude efficacy with gefitinib was similar to docetaxel, but with a more favorable tolerability profile, in the second-line treatment of advanced NSCLC. These results support further investigation of gefitinib in this disease setting.