Objective: Since the prognosis after standard lobectomy for non-small cell lung cancer (NSCLC) in patients with interstitial lung disease (ILD) is poor, we investigated the possibility of sublobar resection for the improvement of the surgical results in such patients. Methods: Of 796 consecutive patients with clinical stage I NSCLC who under-went pulmonary resection, 107 were diagnosed with ILD using high-resolution computed tomography (HRCT). Overall survivals (OS) were compared between patients with non-ILD and those with ILD or between patients with ILD who underwent lobectomy and those who underwent sublobar resection. ILD patterns consisted of usual interstitial pneumonia (UIP), possible UIP, and inconsistent with UIP. The log-rank statistics and Cox proportional hazard models were used to test for survival differences. Results: OS was significantly lower in patients with "ILD inconsistent with UIP'' pattern (hazard ratio [HR], 2.66; 95% confidence interval [CI], 1.19-5.97; P = .014), or "ILD with possible UIP or UIP'' patterns (HR, 2.38; 95% CI, 1.76-3.21; P < . 001) compared with patients with non-ILD. No significant difference in OS was observed between patients with ILD who underwent either lobectomy or sublobar resection (HR, 1.82; 95% CI, 0.81-4.06; P = .19). Multivariable Cox analysis demonstrated diffusing capacity of the lung for carbon monoxide (HR, 0.95; 95% CI, 0.91-0.99; P = .009) and not surgical procedure (HR, 2.76; 95% CI, 0.83-9.16; P = .099), as an independent prognostic factor for OS. Conclusions: Sublobar resection may be a potential alternative choice for clinical stage I NSCLC with ILD on HRCT.