The photodissociation dynamics of [Re(H)(CO) 3 (H-dab)] (H-dab 1,4-diaza-1,3-butadiene) were studied by means of wavepacket propagations on CASSCF/MR-CCI potentials calculated for the electronic ground state and low-lying excited states as a function of two coordinates, q a and q b , that correspond to the ReΓH bond homolysis and to the axial CO loss, respectively. The theoretical absorption spectrum is characterized by two bands, one intense peak centered at l 500 nm (21 000 cm Γ1 ) and one broad band centered at 310 nm (32 500 cm Γ1 ). The visi-ble band was assigned to the low-lying metal-to-ligand charge-transfer (MLCT) states with a main contribution of the a 1 A' 3 c 1 A' transition corresponding to the 3d xz 3 p* dab excitation. The second band calculated in the UV energy domain was assigned to the d 1 A' (s MnΓH 3 p* dab ) state corresponding to a sigmabond-to-ligand charge-transfer (SBLCT) state. The photodissociation dynamics of the low-lying 1 MLCT and 3 SBLCT states following irradiation in the visible energy domain was simulated by wavepacket propagation on the two-dimensional diabatic potentials V(q a , q b ) coupled by the spin-orbit. In contrast to what was found for the manganese analogue, the 1 MLCT state is nonreactive and a rather slow (beyond the ps time scale), nontotal and indirect homolysis of the ReΓH bond occurs through 1 MLCT 3 3 SBLCT intersystem crossing.