A portable optical fibre sensor has been developed for remote monitoring of benzene, toluene, ethylbenzene, p-xylene, m-xylene and o-xylene (BTEX). Firstly, the analyser was tested for calibration and its analytical performance for BTEX monitoring compared with a more classical analytical method, namely gas chromatography coupled to a flame ionization detector (GC-FID). The developed remote sensor shows several analytical advantages such as, high analytical sensitivity and accuracy, good linearity and stability of the analytical signal and short analytical time. Secondly, the optical fibre based sensor was applied to air monitoring for detection and quantification of BTEX in a confined industrial environment. The analytical signal measurement was performed by wireless at 20 m of distance from the local of analysis. Besides, the reported sensor showed a high degree of portability, compact design and high analytical performance for remote BTEX monitoring, in situ and in real-time.