Background: Thymomas but not thymic carcinomas can benefit of cytoreductive surgery even if a complete resection is not achievable. Surgical resection of pleural metastases, the most common site of progression, can be performed in selected patients. We evaluated the outcome of stereotactic body radiation therapy (SBRT) for treatment of pleural metastases in patients’ not eligible for surgery. Methods: We retrospectively identified 22 patients treated with SBRT for pleural metastases between 2004 and 2019. According to RECIST criteria, time to local failure and progression free survival (PFS) were calculated using Kaplan-Meier estimation. Results: Twelve of the 22 patients were male. The median age was 40 years (range 29-73). There were 1 A, 3 AB, 3 B1, 3 B2, 3 B2/B3 and 9 B3 thymomas. The Masaoka stage at diagnosis was IIA in 2, IIB in 7, III in 5, IVA in 7 and IVB in 1 patient. Pleural metastases and primary tumor were synchronous in 8 patients. Thymectomy was performed in 21 patients. Seven patients received pre-operative chemotherapy and 12 post-operative radiotherapy. One patient received chemotherapy and radiotherapy after a macroscopically incomplete thymectomy. Five patients had a single pleural metastatic site and 17 presented multiple localizations. Sixteen patients received SBRT on multiple sites of pleural metastases. At the time of the analysis a patient received SBRT exclusively on one of 3 pleural metastases. The median dose of radiation was 30Gy (range 25-40) given in 3 fractions. Ten patients experienced a progression of treated lesions with a median time to local failure of 25.5 months (95%CI 20.9-30.1). The median PFS was 20.4 months (95%CI 10.7-30). There were not significant differences in PFS between patients diagnosed with synchronous and metachronous metastases (p=0.477), across those treated with chemotherapy or naive (p=0.189) and between those who received or not a previous surgical resection of the pleural metastases (p=0.871). Conclusions: SBRT of pleural metastases is feasible and offer an interesting local control of diseases. The impact of this treatment on patients’ survival is hardly predictable because of the heterogenous clinical behavior of thymomas.