Metal oxide 1D nanowires are probably the most promising structures to develop cheap stable and selective chemical sensors. The purpose of this contribution is to review almost two-decades of research activity at the Sensor Lab Brescia on their preparation during by vapor solid (n-type In₂O₃, ZnO), vapor liquid solid (n-type SnO₂ and p-type NiO) and thermal evaporation and oxidation (n-type ZnO, WO₃ and p-type CuO) methods. For each material we’ve assessed the chemical sensing performance in relation to the preparation conditions and established a rank in the detection of environmental and industrial pollutants: SnO₂ nanowires were effective in DMMP detection, ZnO nanowires in NO₂, acetone and ethanol detection, WO₃ for ammonia and CuO for ozone.