This study addresses the innovative integration of free-free resonant column measurements (FFRC) of body wave velocities in rock specimens with the X-ray microcomputer tomography (micro-CT or μ-CT) imaging. FFRC seismic measurements combined with μ-CT scanning is a novelty manner to execute and interpret dynamic rock core characterization in laboratory. FFRC measurements covers unconstrained compression and shear wave velocities (Vc and Vs) as well as quality factors (Qc and Qs), which were evaluated in the ranges of frequency from ~ 3 to ~ 10 kHz for Berea sandstone specimens and from ~ 10 to ~ 20 kHz for Indiana limestone samples. In addition, the propagation velocity of constrained compression waves, Vp, were measured for all the specimens using direct-travel times. The μ-CT scanning provided micro-structural rock parameters such as porosity, profiles of coefficients of attenuation, as well as pore-size and grain-size distributions. Also, resonance testing allowed us to evaluate the integrity of the rock cores, which could be independently confirmed by using μ-CT scanning along the specimens. Finally, FFRC combined with μ-CT might provide quantitative information to clarify atypical seismic results of rock cores.