It is now well accepted that physical exercise stimulates hippocampal neurogenesis and may promote cognitive ability. Less clear are the mechanisms by which this process occurs. One potential contributing influence, that is usually neglected, is the vestibular system, which by its very nature must be activated during physical exercise and which essentially cannot be turned off without complete bilateral vestibular lesions. This paper reviews a small literature that demonstrates that bilateral vestibular loss (BVL) in rats modulates cell proliferation in the dentate gyrus (DG) and that artificial electrical activation of the vestibular system, using galvanic vestibular stimulation, does also. Although there are only a few piecemeal studies of this subject, because of the way that they were controlled, it is likely that the vestibular system has a regulatory role in cell proliferation in the DG and therefore possibly in neurogenesis, which needs to be taken into account in the interpretation of neurogenesis studies.