Reliable and effective sensors for the accurate detection of hydrogen concentrations in air are essential for the safe operation of fuel cells, hydrogen fuelled systems (e.g. vehicles) and hydrogen production, distribution and storage facilities. The present paper describes the activity on-going at JRC for the establishment of a facility that can be used for testing and validating the performance of hydrogen sensors under a range of conditions representative of those to be encountered in service. Potential aspects to be investigated in relation to the sensors performances are the influence of temperature, humidity and pressure (simulating variations in altitude), the sensitivity to target gas and the cross- sensitivity to other gases/vapors, the reaction and recovery time and the sensors? lifetime. The facility set up at JRC for the execution of these tests is described, including the program for its commissioning. The results of a preliminary test are presented and discussed as an example.