BACKGROUND Transbronchial lung cryobiopsy (TBLC) can be indicated in diffuse parenchymal lung diseases (DPLDs) when a confident noninvasive diagnosis cannot be made. The 2 most relevant complications of TBLC are bleeding and pneumothorax (PTX). The accuracy of chest ultrasonography (US) for the detection of PTX is higher when compared to chest X-ray (CXR) with reference to computed tomography (CT) scan as a gold standard. OBJECTIVE We evaluated the accuracy of chest US in detecting PTX after TBLC in patients with DPLDs. METHODS Patients underwent TBLC during rigid bronchoscopy in deep sedation. Cryobiopsy was performed with fluoroscopic guidance. Three hours later, patients underwent chest US and standard CXR. When there was no concordance between chest US and CXR, chest CT was required. RESULTS Forty-three patients were enrolled into the study. Cryobiopsy was performed in the right lung in 36 (84%) patients. PTX was diagnosed in 10 (23%) patients by CXR. There was complete agreement between radiologists interpreting CXR (k = 1, 95% CI 1). Chest US was positive for PTX in 11 (25%) patients. There was complete agreement between pulmonologists interpreting chest US (k = 1, 95% CI 1). The prevalence of PTX diagnosed by concordance of CXR and chest US was 23% (10/43, 95% CI 11.8-38.7). The sensitivity and specificity of chest US were 90% (95% CI 55.5-99.7) and 94% (95% CI 79.8-99.3), respectively. Moreover, the positive and negative predictive values were 82% (95% CI 48-98) and 97% (95% CI 84-100), respectively. CONCLUSIONS Chest US is a highly sensitive and specific diagnostic tool for the diagnosis of PTX after TBLC.