Simple pulse sequences have been used to determine and isolate most carbon-13 and proton longitudinal relaxation parameters in pure liquid benzene (carbon-13 in natural abundance). The derived parameters include specific longitudinal proton and carbon-13 relaxation rates, direct and remote proton-carbon cross-relaxation rates, proton-proton cross-relaxation rates, and the cross-correlation rate involving direct proton-carbon dipolar interaction and carbon shielding anisotropy (the latter being derived from the evolution of the initially created longitudinal spin order). From these data, it was possible to estimate the dipolar intermolecular contributions to proton and carbon longitudinal nuclear relaxations and the anisotropy of molecular reorientation (the two relevant correlation times are found to be at 25 degrees C : tau(parallel to) = 0.58 ps and tau(perpendicular to) = 1.62 ps; tau(perpendicular to) associated with the tumbling of the symmetry axis perpendicular to the molecular plane and tau(parallel to) associated with rotation around this axis).