The EGFR T790M somatic mutation is the most common mechanism of resistance to tyrosine kinase inhibitors in NSCLC. Patients with advanced disease are not always amenable to repeat biopsy for further molecular analysis. Developing noninvasive methods to detect T790M in cell-free DNA in the absence of tissue is being actively investigated. Unfortunately, the low sensitivity of plasma for detection of T790M has limited its clinical use. Exhaled breath condensate (EBC) is an easily collected sample that is known to harbor cell-free DNA, including lung cancer mutations. This report details the potential utility of exhaled breath condensate in the detection of the EGFR T790M mutation.