Background Idiopathic pulmonary fibrosis is a disease with a poor prognosis and has been associated with increased lung cancer incidence. Case presentation We report the case of a Caucasian 75-year-old woman, a former smoker, hospitalized for breathlessness with a chest computed tomography scan showing an interstitial lung disease. A surgical lung biopsy was performed, confirming a pattern of usual interstitial pneumonia but also numerous disseminated foci of well-differentiated focally invasive squamous cell carcinoma without hypermetabolic lung nodule, mass, or enlarged lymph node visualized on chest computed tomography or positron emission tomography scan. Nintedanib was started for its antifibrotic and antitumor properties, without any other antineoplastic treatment. Three years after initiation of nintedanib, clinical, functional, and computed tomography scan evaluations were stable, and there was no evidence for evolution of the squamous cell carcinoma. Conclusions Data are scarce regarding the benefit of nintedanib in patients with idiopathic pulmonary fibrosis-associated lung cancer, and it is unclear whether nintedanib could have a preventive role in lung carcinogenesis in idiopathic pulmonary fibrosis patients. This experience could help the scientific community in case of similar incidental findings.