375 Background: Stereotactic ablative radiotherapy (SABR) is emerging as a treatment option for patients with oligometastatic prostate cancer. The primary aim of this approach is to prolong disease free survival and delay the initiation of systemic therapies. This retrospective study is aimed to analyse local control, biochemical progression-free survival (b-PFS), toxicity and systemic therapy-free survival in a cohort of patients treated by a single clinician. Methods: Eighteen patients (26 lesions) in patients with relapsed oligometastatic prostate cancer ( 1-3 sites) were treated with SABR, delivered using both cyberknife and VMAT. Doses used were 24 Gy in 2 or 3 fractions for spine and 30 - 40 Gy in 3 fractions for lymph nodes and other bony metastases. All patients had either a Choline or PSMA- PET scan prior to treatment. Response was assessed with PSA testing and repeat scanning when feasible. CTCAE acute and late toxicity was prospectively recorded. Results: Mean age was 68. Previous treatments for the primary prostate cancer included surgery (7 patients), surgery and salvage prostate bed radiotherapy (6 patients), radical radiotherapy (4 patients) and cryotherapy (1 patient). Twelve patients had a single metastatic site, four patients had 2 sites and two patients had 3 sites. Six patients patients were treated with a short course of androgen deprivation therapy (ADT) in addition to SABR. All patients had a fall in PSA with a mean reduction of 75%. Median pre-SABR PSA was 1.83μg/L and median post-SABR PSA was 0.28μg/L. At a median follow-up of 14 months (range 2 - 28.5), 14 patients (78%) remained systemic therapy free. Three patients with a single pelvic lymph node metastases achieved a sustained undetectable PSA level. All 8 patients who had a post-treatment PET scan showed no residual activity at the treated site. One patient experienced G2 acute bowel toxicity, otherwise there was no toxicity above G1. Conclusions: MDT using SABR for relapsed prostate cancer is a safe treatment with promising results in terms of local control, b-PFS and delaying the initiation of systemic therapies. This minimally invasive approach has the potential to improve patients' quality of life, but requires further evaluation in randomised clinical trials.