<p>In this work we have investigated the growth of bismuth nanowires during RF sputtering of a bismuth target onto conductive and insulating substrates with and without electrical contact to a grounded sample holder. It turned out that nanowires on conducting substrates grow only when the substrate is electrically insulated from the sample holder. Measurement of the electrostatic potential on the substrate using a Langmuir probe showed that the substrate isolated from the holder is charged negatively. We assumed that the growth of nanowires is affected by the Coulomb interaction of positively charged Bi ions present in the flow of the sputtered target material with the negatively charged substrate. Irregularities formed on the film surface serve as sites of electric field concentration. Bi ions, attracted to these irregularities, promote earlier nucleation of nanowires and enhance their further growth.</p>