In the field of neuroscience there is interest on manufacturing new recording devices. The relationship between individual action potentials of neurons and field potentials in multicellular records is complex. For this reason, there is a big interest in multielectrode arrays. This work describes the unconventional fabrication process of an alternative multielectrode and its use for sensing neuronal activity. It consists of a matrix of Si nanowires randomly distributed, coated with Ag nanoparticles, and with macrometric Ag back contacts. The Si nanowires are prepared by metal-assisted chemical etching of a Si wafer, which is an economical and highly reproducible technique. Recordings using the multielectrode array of randomly distributed Si nanowires look promising and comparable with recordings obtained with other multielectrode devices.