Background: Stereotactic MR-guided adaptive radiotherapy (SMART) brings several advancements including enhanced soft tissue definition, adaptation of individual fractions based on daily anatomy, real time tracking of prostate coupled with beam gating that prevents treatment delivery if the prostate is outside the treatment boundary and negating the need for invasive fiducial markers. Here we evaluate treatment response and acute and intermediate patient adverse events amongst prostate cancer patients who underwent SMART. Methods: A total of 197 patients with localised prostate cancer were treated with SMART. Patients were assessed for eligibility against robust institutional criteria. SMART consisted of MR- and computed tomography (CT) simulation scan, inverse intensity-modulated radiotherapy (IMRT) treatment planning and daily plan re-optimization prior to treatment delivery with editing CTVs (as per daily variation) and OAR recontouring within the first 3 cm outside the PTV. Prescription dose was 36.25 Gy in 5 fractions delivered on alternate days. Patients who completed a baseline 12 item PRO-CTC AE, before treatment, were subsequently followed up with the same graded questionnaire at set time points. Results: Median follow up was 12 months (inter quartile range 6 – 36). Patients included low (6%), intermediate (86%) and high risk (8%). Median pre-treatment PSA was 7.09 ng/ml (interquartile range IQR 1 – 133.2). At first follow up at 6 months, median drop in PSA was 97.09 % from base line (range 27.7– 99.9 %, SD 15.04). At second follow up at 12 months, median change in PSA was 96.92% (range 5.88– 233.3%, SD 12.41). At 24 months median PSA was 0.28 ng/ml (IQR 0.03 -3.26) with a median drop from baseline of 95.98%. ADT was used in 88% of patients and median duration of ADT was 6 months (IQR 3-30). 69 patients, who completed baseline and subsequent PRO CTC AE questionnaires in different time frames were included in analysis. More than 80% of men reported no change from baseline urinary toxicity during follow up apart from urinary urgency. Regarding GI toxicities, new ≥ frequent/severe patient reported adverse events were diarrhoea (9%), constipation (3%) and pain on opening bowels (6%) in the first 3 months but were all absent after 33 months. No patient reported frequent GI bleeding. No grade ≥4 toxicity was seen. Conclusions: SMART shows low acute and intermediate toxicities and excellent short-term outcomes.