ObjectiveTo report the 5‐year failure‐free survival (FFS) following high‐intensity focused ultrasound (HIFU).Patients and MethodsThis observational cohort study used linked National Cancer Registry data, radiotherapy data, administrative hospital data and mortality records of 1381 men treated with HIFU for clinically localised prostate cancer in England. The primary outcome, FFS, was defined as freedom from local salvage treatment and cancer‐specific mortality. Secondary outcomes were freedom from repeat HIFU, prostate cancer‐specific survival (CSS) and overall survival (OS). Cox regression was used to determine whether baseline characteristics, including age, treatment year, T stage and International Society of Urological Pathology (ISUP) Grade Group were associated with FFS.ResultsThe median (interquartile range [IQR]) follow‐up was 37 (20–62) months. The median (IQR) age was 65 (59–70) years and 81% had an ISUP Grade Group of 1–2. The FFS was 96.5% (95% confidence interval [CI] 95.4%–97.4%) at 1 year, 86.0% (95% CI 83.7%–87.9%) at 3 years and 77.5% (95% CI 74.4%–80.3%) at 5 years. The 5‐year FFS for ISUP Grade Groups 1–5 was 82.9%, 76.6%, 72.2%, 52.3% and 30.8%, respectively (P < 0.001). Freedom from repeat HIFU was 79.1% (95% CI 75.7%–82.1%), CSS was 98.8% (95% CI 97.7%–99.4%) and OS was 95.9% (95% CI 94.2%–97.1%) at 5 years.ConclusionFour in five men were free from local salvage treatment at 5 years but treatment failure varied significantly according to ISUP Grade Group. Patients should be appropriately informed with respect to salvage radical treatment following HIFU.