This study reports on experimental results concerning methyl-tert-butyl-ether (MTBE, C5H12O) adsorption from water into the pores of siliceous zeolite ferrierite (FER) by combining powder X-ray diffraction analyses and chromatography techniques. Rietveld structure refinement (Immm space group) highlighted the presence of two crystallographically independent MTBE sites located in the 10-ring channel parallel to the [001] direction (MTBE1) and in the ferrierite cage (MTBE2), respectively. On the whole, Rietveld refinement revealed clearly the incorporation of ~1.8 MTBE molecules per unit cell, in very good agreement with the weight loss given by thermogravimetric analyses, and saturation capacity as determined by adsorption isotherms. Rapid kinetics combined with good adsorption suggests that FER can be used beneficially as an adsorbent medium in removing this emerging organic contaminant from water.