Due to state-of-art analytical techniques, non-invasive exhaled volatile organic compounds (VOCs) analysis has become a potential method for early diagnosis of lung cancer. We collected breath samples from 43 patients with non-small cell lung cancer (NSCLC) and 41 normal controls using Tedlar^® gas bags. The VOCs were extracted with solid phase micro-extraction (SPME) and analyzed by gas chromatography (GC)/mass spectrometry (MS). The number of VOCs detected in each breath sample ranged from 68 to 114. Among the VOCs 1-butanol and 3-hydroxy-2-butanone were found at significantly higher concentrations in breath of the lung cancer patients compared to the controls. VOCs levels were not significantly different between early stage lung cancer patients and late stage lung cancer patients. Lung adenocarcinoma was significantly related to higher VOCs concentrations in the breath. Our data showed that 1-butanol and 3-hydroxy-2-butanone in breath could possibly be taken as useful breath biomarkers for discerning potential lung cancer patients and VOCs analysis could be used as a complementary test for the diagnosis of lung cancer. © 2009 Elsevier Ireland Ltd. All rights reserved.