Background: The diagnosis of organizing pneumonia (OP) often requires histological confirmation. The aim of this retrospective study was to evaluate the diagnostic yield and complication rate of radial endobronchial ultrasound (r-EBUS) for OP. Methods: All patients who had r-EBUS as a first diagnostic procedure for a peripheral pulmonary lesion at Rouen University Hospital, France, between April 2008 and December 2020 were included. Cases without a final diagnosis of OP or follow-up were excluded. Patients, lesions, and r-EBUS characteristics were retrospectively analyzed. Results: 2735 r-EBUS procedures were performed, and 33 cases with final OP could be analyzed. Procedures were performed under local anesthesia in 28/33 cases (85%). Among the 33 final OP cases, 17 were considered cryptogenic, and 16 secondary. The lesions were patchy alveolar opacities in 23 cases (70%), masses or pulmonary nodules in 8 cases (24%), and diffuse infiltrative opacities in 2 cases (6%). A bronchus sign on CT scan was found in all cases. In 22 cases (67%), a histopathological diagnosis was obtained from the r-EBUS samples. In 4 cases (12%), histopathological diagnosis was made by surgery, and in 7 cases (21%) the diagnosis was made based on clinical, radiological, and evolution features. An ultrasound image was found in 100% (22/22) of cases in the r-EBUS positive (r-EBUS+) group vs. 60% (6/10) in the r-EBUS negative (r-EBUS-) group, respectively (p < 0.002). The diagnostic yield of r-EBUS for OP was 67% and increased to 79% (22/28) when an ultrasound image was obtained. The median time between CT scan and r-EBUS procedure was 14 days (3–94): 11.5 days in the r-EBUS+ group and 22 days in the r-EBUS- group (p < 0.0001). No severe complications were reported. Conclusion: r-EBUS, when performed shortly after a CT scan showing a bronchus sign, is an efficient and safe technique for OP diagnosis.