During the last 2 decades, the introduction of new isotopes for both removable (192Ir) and permanent (125I) interstitial implants, along with the availability of computerized dosimetry and the refinement of implantation techniques have all contributed to a Renaissance of brachytherapy. Techniques of implantation and the results of such procedures at the Stanford Medical Center for the 3 most commonly implanted carcinomas (breast, prostate, head and neck) are all presented in detail. Other anatomic sites which may be treated by interstitial irradiation are also described.