Differential sticking arises in drilling operations when the drillstring embeds into a layer of mud on the borehole wall. The present work is aimed at proving the concept of an unconventional method of releasing the drill string, namely, the application of an electrical current. An instrument has been designed and constructed to measure the slippage torque at the interface between a steel disc and a filtercake prepared from a model aqueous drilling mud. Experiments have demonstrated that a cathodic current of 1 mA cm(-2) reduced the slippage torque by about 50% with both mild and stainless steel. The same effect was obtained galvanically, using a magnesium sacrificial anode connected to the steel, thus dispensing with the need for an external power source. It is hoped that this effect could be used to inhibit differential sticking in aqueous drilling muds, as well as offering a fast method of stuck pipe release.