The relation between mental and manual rotation was investigated in 2 experiments. Experiment 1 compared the response times (RTs) of mental rotation about 4 axes in space with the RTs shown in the same task when participants were allowed to reorient the stimuli by means of rotational hand movements. For the 3 Cartesian axes, RT functions were quantitatively indistinguishable. Experiment 2 investigated interference between mental rotation and 4 kinds of simultaneously executed hand movements that did not reorient the stimuli. Interference was observed only when axes of manual and mental rotation coincided in space. Regardless of the hand used, concordant rotational directions facilitated, whereas discordant directions inhibited, mental rotation. The results suggest that mental object rotation and rotatory object manipulation share a common process that is thought to control he dynamics of both imagined and actually performed object reorientation.