The technique of puncture and dilatation 'in the hands of one' is described in detail based on almost 800 percutaneous operations on the kidney. All of the steps of the operation were carried out by the urologist himself. The advantages are presented and two new percutaneous instruments are introduced: a percutaneous working sheath and the lumbotome, a wire-guided, double-blade knife for cutting the percutaneous tract. The principle of percutaneous stone operation is explained as well as special complications which can occur. Finally, statistic results are discussed which clearly show a remarkable decrease of the residual and recurrent stone rate in comparison to conventional kidney stone surgery.