Potentiometry is a very simple electrochemical technique with extraordinary analytical capabilities. It is also well known that nanostructured materials display properties which they do not show in the bulk phase. The combination of the two fields of potentiometry and nanomaterials is therefore a promising area of research and development. In this report, we explain the fundamentals of potentiometric devices that incorporate nanostructured materials and we highlight the advantages and drawbacks of combining nanomaterials and potentiometry. The paper provides an overview of the role of nanostructured materials in the two commonest potentiometric sensors: field-effect transistors and ion-selective electrodes. Additionally, we provide a few recent examples of new potentiometric sensors that are based on receptors immobilized directly onto the nanostructured material surface. Moreover, we summarize the use of potentiometry to analyze processes involving nanostructured materials and the prospects that the use of nanopores offer to potentiometry. Finally, we discuss several difficulties that currently hinder developments in the field and some future trends that will extend potentiometry into new analytical areas such as biology and medicine.