Background: Radial probe endobronchial ultrasound-guided transbronchial lung biopsy (RP-EBUS-TBLB) is widely used for diagnosis of peripheral lung lesions (PLLs). To date, there have been no reports regarding the clinical outcomes of RP-EBUS-TBLB for PLLs in patients with idiopathic pulmonary fibrosis (IPF). Objectives: This study was performed between October 2017 and December 2019 to identify the safety and diagnostic performance of RP-EBUS-TBLB in IPF patients. Methods: Patients were divided into the usual interstitial pneumonia (UIP) group (n = 39, 4%), the probable UIP group (n = 12, 1%), and the noninterstitial lung disease (non-ILD) group (n = 903, 95%). Results: The diagnostic yield was significantly lower in the UIP group than in the non-ILD group (62% vs. 76%; p = 0.042), but there were no significant differences between the UIP and probable UIP groups (62% vs. 83%; p = 0.293) or the probable UIP and non-ILD groups (83% vs. 76%; p = 0.741). Multivariate logistic analysis showed that the mean diameter of PLLs, positive bronchus sign on CT, and “within the lesion” status on EBUS were independently associated with success of the procedure. Especially, the presence of the UIP pattern on CT (OR, 0.385; 95% CI: 0.172–0.863; p = 0.020) was independently associated with failed diagnosis. Among patients with UIP, “within the lesion” status on EBUS (OR, 25.432; 95% CI: 2.321–278.666; p = 0.008) was shown to be a factor contributing to a successful diagnosis. Overall, there were no significant differences in complication rates among the 3 study groups. Conclusion: RP-EBUS-TBLB can be performed safely with an acceptable diagnostic yield, even in patients with IPF.