PURPOSE: Bronchopleural fistula (BPF) is a serious complication of lung resection. To avoid BPF, the bronchial stump/anastomotic site is often covered with a flap of surrounding tissue. One risk factor for BPF is radical lung resection after induction chemoradiotherapy for lung cancer. We retrospectively reviewed our database to elucidate the characteristics of tissue flaps that prevent BPF. METHODS: This retrospective study included 152 patients treated between 1999 and 2019. We examined the clinicopathological characteristics, including the type and thickness of the tissue flap used to cover the bronchial stump/anastomotic site, and postoperative complications, including BPF. RESULTS: BPF occurred in 5 patients (3.3%). All 5 patients had complications that could have affected delayed wound healing, such as pneumonia. The covering tissue flap thickness was significantly greater in patients without BPF than in those who developed BPF (p = 0.0290). Additionally, the tissue flap thickness was significantly greater than in those with BPF (p = 0.0077), even in high-risk patients who developed pneumonia or radiation pneumonitis on the operative side within 6 months postoperatively. CONCLUSION: Perioperative management is crucial to avoid complications affecting the healing of the bronchial stump/anastomotic site, and the covering tissue flap thickness may be an important factor in avoiding or minimizing BPF.