  The single-cluster Monte Carlo algorithm and the reweighting technique are
used to simulate the 3D-ferromagnetic Ising model on three dimensional
Voronoi-Delaunay lattices. It is assumed that the coupling factor $J$ varies
with the distance $r$ between the first neighbors as $J(r) \propto e^{-ar}$,
with $a \ge 0$. The critical exponents $\gamma/\nu$, $\beta/\nu$, and $\nu$ are
calculated, and according to the present estimates for the critical exponents,
we argue that this random system belongs to the same universality class of the
pure three-dimensional ferromegnetic Ising model.
