In this paper, we show the results of experiments of InAs nanowire (NW) growth on (111)-oriented Si wafers. The NWs, grown at 620 °C by metal–organic vapor-phase epitaxy, are vertically aligned and ∼30 nm in diameter. Their structural properties are studied by transmission electron microscopy, evidencing a polytypic character, and the vibrational properties by Raman spectroscopy. An assessment of their electrical transport properties is carried out by measuring back-gated, single InAs NW field-effect transistors. The absence of a catalyst ensures the compatibility of the NW growth process with current CMOS technology.