Fluorine-doped tin oxide (F-SnO2) nanoparticles were prepared via the “benzyl alcohol route” assisted by microwave radiation. The samples were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and impedance spectroscopy. The synthesized F-SnO2 nanoparticles showed a high degree of crystallinity and rather uniform size and shape. They were used as sensing layer in resistive sensors and their sensing properties towards H2 were tested. The developed sensor showed high sensitivity upon exposure to H2 gas, in the concentration range 0 - 4% in air, and extremely fast response and recovery time.