This study has investigated the resistance to failure in torsion of dental posts made from cast and wrought alloys. Torsional tests were carried out on five dental materials: cast palladium silver and cast yellow gold, and wrought cobaltchromium, stainless steel and titanium wires, and the strain to failure measured. The fractured surfaces were examined by optical microscopy to determine the mode of failure and the Vickers hardnesses of the materials measured. It was found that the resistance to torsional failure was, in order of highest to lowest: titanium, stainless steel, cobalt-chromium, yellow gold and palladium silver. Both titanium and yellow gold failed only in a ductile mode, whilst palladium silver failed mainly in brittle mode. Stainless steel and cobalt chromium exhibited areas of both brittle and ductile failure. The samples of cast palladium silver rods varied widely in their behaviour, suggesting that considerable differences in physical properties can result, despite contemporaneous production.