  The quasinormal modes for scalar and spinor fields in the background
spacetime corresponding to an $f(R)$ global monopole are calculated using the
WKB approximation. In the obtained results we emphasize the role played by the
parameter $\psi_{0}$, associated with the $f(R)$ gravity. We discuss the
appropriate limit $\psi_{0} \rightarrow 0$, in which case the results
concerning to the Schwarzschild black hole are obtained, as it should be
expected.
