The treatment of localized prostate cancer with high-intensity focused ultrasound (HIFU) has been researched since the 1990s and today the treatment is an actively used therapy for the disease. HIFU works in two ways to destroy tissue, namely thermal and mechanical effects. The most recent data on the Ablatherm HIFU device come from an international registry (@-Registry) and indicate a 5-year biochemical survival rate of 85%. HIFU is commonly used in conjunction with transurethral resection of the prostate in order to reduce prostate gland size and facilitate effective tissue destruction. An additional benefit of HIFU is that it can be used as salvage therapy after radical prostatectomy and external-beam radiotherapy. A new area of research with HIFU involves focal therapy, where tumor sites within the gland are directly targeted with the objective of reducing morbidity.