High-intensity focused ultrasound (HIFU) is a minimally invasive alternative for patients with localized prostate cancer, not suitable for radical prostatectomy because of a life expectancy less than 10 years or because of major co-morbidities precluding surgery. HIFU can be performed in patients with LUTS (associated TURP) or with a previous history of BPH surgery. HIFU is repeatable after the initial procedure if a recurrent cancer is diagnosed on control biopsies. Furthermore, this therapy is a viable option for patients with a local relapse after external beam radiation therapy: oncologic efficacy is conversely related to the initial prostate cancer stage before radiation therapy.