Objective To investigate the effects of iron on the expression and regulation of divalent metal transporter 1 (DMT1) that may play an important role in the physiological brain iron metabolism. Methods Both the contents of ferric and ferrous iron as well as DMT1 (+IRE) and DMT1 (-IRE) protein expression were evaluated with iron histochemistry and immunohistochemistry in cerebral cortex (CC) after intracerebroventricular injection (ICV) of 500μg iron dextran/day for 3 or 7 days (each group contained 6 rats). Results Iron histochemistry results showed that both the ferric and ferrous iron levels in CC were altered obviously after ICV for 7 days. Immunohistochemistry results indicated that the expression of DMT1 (+IRE) in CC was not altered significantly after 3 days of ICV. Whereas the expression of DMT1 (+IRE) was increased significantly after 7 days of ICV when ferrous iron was increased significantly. Contrary to that of DMT1 (+IRE) expression in the same region, there were no significant alterations in DMT1 (-IRE) expression in CC in spite of the existence of the altered brain iron levels, compared with that of control groups. Conclusion These data demonstrate that DMT1 (+IRE) expression is correlated primarily with brain iron levels; especially, its regulation is correlated positively with iron (ferrous iron) in adult rat CC, compared with those of saline-injected control rats.The effect of iron on the different isoforms of DMT1 expression may be different in different brain regions, but further investigations are needed to clarify these issues.