In men with locally advanced/high-risk prostate cancer, there is an ongoing challenge to achieve improved results. Dose escalation studies using three-dimensional conformal radiotherapy (3D-CRT) or intensity modulated radiation therapy (IMRT) have shown benefit particularly in the intermediate and poor risk groups of patients. Of concern, however, is the increase in documented rectal toxicity. High-dose rate brachytherapy (HDR-BT) as a boost in combination with external beam radiotherapy (EBRT) is an alternative strategy of dose escalation that can potentially achieve an even higher biological equivalent dose (BED) to the tumour. The results so far are very encouraging for men with poor prognosis disease. Moreover the technique is associated with very low rates of acute and late toxicity.