A novel route is presented for the fabrication of chromium (III) hexacyanoferrate(II) (Crhf) nanoparticles attached to single-walled carbon nanotubes (SWNTs) modified glassy carbon electrodes (GCE). The morphological character of the Crhf/SWNTs nanocomposites was examined using scanning electron microscopy (SEM), transmission electron microscopy, UV-Vis spectroscopy and Fourier transform infrared spectrometry. The performance of the Crhf/SWNTs nanocomposite modified electrode was characterized using cyclic voltammetry and amperometry. The electrode exhibits efficient electron transfer ability and high electrochemical response towards hydrazine. Moreover it showed a wide linear working range (0.5–500 μM hydrazine), with a detection limit of 0.45 μM estimated at a signal to noise ratio of 3. Response time is fast (about 3 s) and the electrode exhibited good reproducibility and long-term stability.