  The regular graph of ideals of the commutative ring $R$, denoted by
${\Gamma_{reg}}(R)$, is a graph whose vertex set is the set of all non-trivial
ideals of $R$ and two distinct vertices $I$ and $J$ are adjacent if and only if
either $I$ contains a $J$-regular element or $J$ contains an $I$-regular
element. In this paper, it is proved that the radius of $\Gamma_{reg}(R)$
equals $3$. The central vertices of $\Gamma_{reg}(R)$ are determined, too.
