The electric nuclear quadrupole moment (NQM) of lutetium was determined by means of the molecular method. This method combines accurate calculations of electric field gradients (EFGs) at the nucleus with experimental values of nuclear quadrupole coupling constants (NQCCs). Relativistic Dirac-Coulomb coupled cluster calculations were performed to obtain the EFGs at lutetium in LuF and LuCl. These values were supplemented by a Gaunt interaction correction and a correction for the effect of truncating the active space on the electron correlation energy. Our results indicate that the NQMs of Lu-175 and Lu-176 are given by 3415(34) and 4818(48) mbarn, respectively. (C) 2007 Elsevier B.V. All rights reserved.