Gas sensors have been prepared by using single crystalline $\mathrm{Mo}{\mathrm{O}}_3$ nanorods. Structures $50–150\mathrm{nm}$ and up to $15\mu \mathrm{m}$ in length were synthesized by template directed hydrothermal synthesis. Gas sensing tests showed responses to $\mathrm{N}{\mathrm{O}}_2$ up to 740% and to $\mathrm{N}{\mathrm{H}}_3$ up to 570%. Moreover, preliminary electrical characterizations were performed, as a function of temperature in $20–520°\mathrm{C}$ range temperature, by means of current-voltage measurements. $I\text{-}V$ dependence studies show a linear increase in current at low voltage and a quadratic increase at higher voltages. A study of the current-temperature dependence shows that at high temperature current is thermally active and successively decreases that can be explained by taking in account a change of material morphology.