Idiopathic interstitial pneumonias (IIPs) are associated with increased risk of lung cancer. In Japan, acute exaberation of IIPs induced by anticancer treatment is a critical issue. For this reason, there is limited available evidence regarding the optimal treatment approach for lung cancer patients complicated with IIPs. Our previous prospective pilot study demonstrated the safety and efficacy of weekly paclitaxel in combination with carboplatin for advanced non-small-cell lung cancer (NSCLC) with IIPs. The current study was conducted to confirm the results of the same combination therapy used in a larger patient population.Chemotherapy-naïve patients with advanced stage or post-operative recurrent NSCLC patients complicated by IIPs were enrolled. Patients received paclitaxel (100 mg/m) on days 1, 8, and 15, and carboplatin (AUC 5.0) once every 4 weeks.Thirty-three of 35 enrolled patients were evaluable for analysis and received a median of four treatment cycles (range 1-6). Four patients (12.1%; 95% confidence interval 3.4-28.2%) had acute exacerbation (AEx)-related IIPs to the study treatment. However, no fatalities due to AEx were observed. The overall response was 69.7%. The median progression-free survival, median survival time, and 1-year survival were 6.3 months, 19.8 months, and 55.4%, respectively.The efficacy of carboplatin plus weekly paclitaxel treatment for advanced NSCLC patients with IIPs was comparable to that of conventional chemotherapy in advanced NSCLC patients without IIPs. Moreover, the primary endpoint was set to the frequency of treatment-related acute exacerbation, and the primary endpoint was met. These results suggest that patients with advanced NSCLC complicated by IIPs may benefit from this combination chemotherapy.