The growing interest in high-intensity focused ultrasound (HIFU) technology is mainly due to its many potential applications as a new energy source and as noninvasive therapy. It has been introduced to urological oncology as a transrectal treatment for prostate cancer and as extracorporeal treatment for kidney cancer. Although its application in the kidney is still at the clinical feasibility phase, HIFU technology is currently being used in daily practice in Europe for the treatment of prostate cancer. Reports in the literature describing results of HIFU for prostate cancer are mainly based on monocentric, prospective clinical studies. The latest published results suggest that HIFU treatment is a valuable option for well-differentiated and moderately differentiated tumors, as well as for local recurrence after external beam radiation. Two different devices for transrectal treatment of prostate cancer are available, which are essentially different in technology, application mode, published results, and side effects.HIFU in locally recurrent cancer after surgery, as well as adjuvant HIFU for local debulking in locally advanced or metastatic disease, shows promising first results for reducing local disease-induced morbidity and for delay of progression.