Quarkonium measurements in Pb-Pb and p-Pb collisions with ALICE at the LHC

The ALICE experiment has measured quarkonium production in Pb-Pb collisions at \sqrt{sNN} = 2.76 TeV and in p-Pb collisions at \sqrt{sNN} = 5.02 TeV. The measurements are performed in the dielectron de- cay channel at mid-rapidity (|yLAB| < 0.9) and in the dimuon decay channel at forward rapidity (2.5 < yLAB < 4). We focus in particular on the J/{\psi} nuclear modification factor measured both in Pb-Pb and p- -Pb collisions and on the {\Upsilon}(1S) nuclear modification factor measured in Pb-Pb collisions.