The treatment of clinically localized prostate cancer is based on total prostatectomy, radiotherapy or surveillance. The adverse effects of these treatments have led to an increasing interest in alternatives with decreased morbidity. Brachytherapy consists of placing radioactive sources in the prostatic tissue. High doses can therefore be delivered to the cancer while avoiding excessive irradiation of the bladder and rectum. Brachytherapy generally uses permanent implants (Iodine 125 or Palladium 103). The so-called Seattle technique requires planning before implantation, while, in the "ProCeed" technique, the position of the grains is determined at the time of treatment, with the help of a computer programme which determines the dosimetry. Brachytherapy is a reliable and reproducible technique with minimal morbidity, providing 10-year results comparable to those of total prostatectomy.