In this letter, radio-frequency characterization of fully transparent thin-film transistors (TFTs) based on chemically synthesized nanowires (NWs) has been carried out. The NW TFTs show current-gain cutoff frequency fT of 109 MHz and power-gain cutoff frequency fmax of 286 MHz. The TFTs were fabricated on glass substrates using aligned SnO2 NWs as the transistor channel and sputtered indium-tin-oxide films as the source-drain and gate electrodes. Besides exhibiting > 100-MHz operation frequencies, the transparent NW TFTs show a narrow distribution of performance metrics among different devices. These results suggest the NW-TFT approach may be promising for high-speed transparent and flexible integrated circuits fabricated on diverse substrates.