  In this paper, we discuss the region unknotting number of different classes
of 2-bridge knots. In particular, we provide region unknotting number for the
classes of $2$-bridge knots whose Conway notation is $C(m,\ n), C(m,\ 2,\ m),$
$ C(m,\ 2,\ m\pm1)$ and $C(2,\ m,\ 2,\ n)$. By generalizing, we also provide a
sharp upper bound for all the remaining classes of $2$-bridge knots.
