Quantum chemical calculations based on density functional theory have been performed on ruthenocene. Excellent agreement is obtained with ground- and excited-state properties derived from optical spectroscopy. In particular, the energies of the first d–d excitations, the unusually large Stokes shift, the structural expansion of Ru(cp)2 and the substantial reduction of the Ru-cp force constant in the first triplet excited state are almost quantitatively reproduced. The lowest-energy excitation is found to have substantial charge transfer character.