Brachytherapy practice patterns have changed dramatically in the past 10 years, marked by diminishing numbers of gynecologic, head and neck, and breast boost patients; the increasing use of fractionated high-dose-rate therapy for partial breast irradiation and prostate cancer; and a dramatic increase in prostate cancer patients receiving permanent-seed brachytherapy. Intravascular brachytherapy, recently expected to become the most frequent indication for brachytherapy, seems to be receding in importance except for highly selected patients. Overall, the use of brachytherapy seems to be rapidly increasing. Both emerging and established applications of brachytherapy now place much more emphasis on accurate dosimetry, image guidance, and image-based dose evaluation than was the case a decade ago. Brachytherapy is an active area of physics and engineering research that is tending move this modality away from its traditional surgical and empirical approach to a much more quantitative image-guided therapy similar to that of external beam therapy.