A silica-supported monometallic tungstophosphoric heteropoly acid (HPA), H3PW12O40, is a novel and efficient catalyst for the hydrodesulfurization of dibenzothiophene (DBT), Over a 30 wt,% HPA/SiO2 catalyst in a trickle bed flow reactor at industrially relevant gas and liquid space velocities (GHSV 600 h(-1) and LHSV 6 h(-1)) and an H-2 pressure of 30 bar, the hydrodesulfurization proceeds with a DBT conversion of 58% at 290 degreesC and 80% at 350 degreesC. These values are comparable to the performance of the industrial Co-Mo/Al2O3 catalyst. No loss of catalytic activity was observed for a period of 56 h. P-31 MAS NMR and thermogravimetric analysis (TGA) data show that the HPA decomposes upon interaction with H2S/H-2 to yield the active hydrodesulfurization catalyst.