Different lines of research suggest that our mental representations of time and space are linked, though the strength of this linkage has only recently been addressed for the front-back mental timeline (Eikmeier, Schröter, Maienborn, Alex-Ruf, & Ulrich, 2013). The present study extends this investigation to the left-right mental timeline. In contrast to what was found in the cited previous study, the obtained space-time congruency effects were smaller than benchmark stimulus-response congruency effects in control conditions. This pattern of results suggests that the representations of time and space are less strongly linked for the left-right axis than for the back-front axis.