Mixtures consisting of zirconocene difluorides Cp'2ZrF2 (Cp'= substituted or nonsubstituted eta(5)-cyclopentadienyl) as pre-catalysts and diisobutylaluminumhydride i-Bu2AlH as activator were found to be active catalysts in the room-temperature hydrodefluorination (HDF) of fluorinated pyridines. Evaluation of these systems established rac-(ebthi)ZrF2 (1) and Cp2ZrF2 (3) together with i-Bu2AlH as active catalysts in the room-temperature hydrodefluorination (HDF) of pentafluoro-pyridine. The active species for the conversion were the actually formed hydrides [rac-(ebthi)ZrH(mu-H)](2) (2) and [Cp2ZrH(mu-H)](2) (4). The results we obtained (rt, 24h, turn over number 67) showed a significantly better performance compared to other investigations published before for this HDF reaction. (c) 2006 Elsevier B.V. All rights reserved.