A 67-year-old man was referred for the evaluation of a lung lesion. The patient complained of a productive cough of three weeks duration and a chest CT scan showed the presence of multiple nodules with GGO in both lung fields. As fiber optic bronchoscopy with a TBLB was not diagnostic, a chest radiologist with two years of experience performed a CT-guided PCNB with the use of an 18-gauge ACN biopsy needle (Angiotech) in a patient placed in the supine position. However, the mental status of the patient deteriorated rapidly just after the biopsy, which was followed by convulsions and left side hemiparesis. A careful review of chest CT scans obtained during the procedure revealed the presence of air fluid level in the descending aorta (Fig. 3). Brain CT scans and MRI were checked, but no abnormality was evident. According to the temporal relationship between the neurological signs and the biopsy procedure, we made a presumptive diagnosis of a cerebral air embolism. Ninety hours after the event, the patient underwent HBOT (100% oxygen, 2.2 atmospheres for 60 minutes). The mental status improved after HBOT and one day later the patient underwent one additional HBOT session. A TTE was normal. The patient was discharged without any neurological sequelae.