High-intensity ultrasound can selectively destroy tissue if delivered in a focused manner without damage to the surrounding tissue. High-intensity focused ultrasound (HIFU) in the treatment of localized prostate cancer can deliver a minimally invasive treatment with effective cancer control. Of particular note, HIFU has the ability to deliver focal therapy of only the malignant lesions within the prostate. One of the advantages of HIFU has been purported to be its repeatability in men who have residual prostate cancer. Patients on anticoagulant therapy, such as warfarin or aspirin, can be kept on their anticoagulant regimens. Recent improvements to the device allow the monitoring of changes in the estimated tissue temperature at the point where HIFU is delivered during HIFU therapy, supporting its authenticity. The idea of treating only the cancer within the prostate and sparing the non-cancerous tissue in the prostate is quite appealing. Some evidence prompted us to use HIFU for focal therapy of a limited area of the prostate in low-risk patients. Consequently, HIFU has been considered to be a forerunner in minimally invasive and focal treatment of localized prostate cancer.