A revised method for implanting plastic tubes used to carry 192iridium for brachytherapy is described. Solid malleable stainless steel needles are machined at one end with a tapered screw thread, on to which the plastic tubing can be placed for pulling through tissue. The technique has proved to be both simpler and quicker than the standard 'Amersham' method. Since the solid needles may be moulded, it is easier to implant relatively inaccessible areas such as axillary, intrathoracic and paraspinal sites. For sites with no clear exit point for the needles, a large diameter steel needle is described, which enables the plastic tubes to be inserted with less trauma to the tissues.