The dissolution rate of cadmium from six different dental gold solder alloys was determined in anin vitropotentiostatic study. The measurements were made in the potential range 740—880 mV and attempts have been made to extrapolate the results to a potential region that might in reality occur in the oral cavity. For comparison the dissolution rates of copper and zinc were also determined. Electrochemically the most interesting quantity was the logarithm of the dissolution rate because it is a linear function of the applied potential. This linear relationship was given by the Tafel equation. The dissolution rate of cadmium was shown to be rather small even under circumstances which may be said to represent very unfavourable conditions within the oral cavity.