Non-small-cell lung cancer (NSCLC) is often associated with a range of debilitating disease-related symptoms, which can lead to diminished quality of life (QoL). The Functional Assessment of Cancer Therapy-Lung (FACT-L) questionnaire has been validated as a reliable and sensitive means of assessing QoL domains that are relevant to patient outcomes and includes a Lung Cancer Subscale (LCS) designed to assess lung-based symptoms. Two phase II gefitinib ('Iressa', ZD1839) monotherapy trials, IDEAL 1 and 2, investigated the effect of gefitinib on a number of endpoints, including disease-related symptoms and QoL, in patients with refractory advanced NSCLC. Rapid symptom improvement (SI) lasting for at least one month was seen in >40% of patients receiving gefitinib 250 mg/day. SI was correlated with objective tumour response, improvement in performance status and median survival. Both SI and objective response were predictive of patient survival.