The aim of this study was to explore the effects of presurgical exercise training on quality of life (QOL) in patients with malignant lung lesions. Using a single-group prospective design, patients were enrolled in supervised aerobic exercise training for the duration of surgical wait time (mean 59.7 days). Participants completed assessments of cardiorespiratory fitness (peak oxygen consumption) and QOL using the Functional Assessment of Cancer Therapy-Lung scales, including the trial outcome index (TOI) and the lung cancer subscale (LCS) at baseline, immediately presurgery, and postsurgery (mean, 57 days). 9 participants provided complete data. Repeated-measures analysis indicated a significant effect for time on TOI (P = .006) and LCS (P = .009). Paired analysis revealed that QOL was unchanged after exercise training (ie, baseline to presurgery), but there were significant and clinically meaningful declines from presurgery to postsurgery in the LCS (-3.6, P = .021) and TOI (-8.3, P = .018). Change in peak oxygen consumption from presurgery to postsurgery was significantly associated with change in the LCS (r = 0.70, P = .036) and TOI (r = 0.70, P = .035). Exercise training did not improve QOL from baseline to presurgery. Significant declines in QOL after surgery seem to be related to declines in cardiorespiratory fitness. A randomized controlled trial is needed to further investigate these relationships.