The critical review discusses the key points of the main blocks leading to the development and use of an amperometric sensing system. On the one side, most attention is paid to the electrode materials that may potentially induce impressive progresses in the performance of the device. On the other side, comparable room is given to the remaining parts constituting the sensing system as a whole, from tests in different solutions to problems arising from data processing. All these steps require care and knowledge of the manifold branches of science and technology that concur to realise and use the device at best. However, some of these aspects are too often underestimated, also due to the different scientific origin of researchers or analysts who are directly involved. The discussion is centred on both the virtues of amperometric sensing systems and on the limits they present. The last are especially evidenced, in order to induce full consciousness of the complexity and interdisciplinary features of this kind of analytical tools. Exemplificative literature dealing with the issues dealt with is cited and critically inserted in the frame of the overall picture.