  Shear viscosity $\eta$ is calculated for the nuclear matter described as a
system of interacting nucleons with the van der Waals (VDW) equation of state.
The Boltzmann-Vlasov kinetic equation is solved in terms of the plane waves of
the collective overdamped motion. In the frequent-collision regime, the shear
viscosity depends on the particle-number density $n$ through the mean-field
parameter $a$, which describes attractive forces in the VDW equation. In the
temperature region $T=15 - 40$~MeV, a ratio of the shear viscosity to the
entropy density $s$ is smaller than 1 at the nucleon number density $n =(0.5 -
1.5)\,n^{}_0$, where $n^{}_0=0.16\,$fm$^{-3}$ is the particle density of
equilibrium nuclear matter at zero temperature. A minimum of the $\eta/s$ ratio
takes place somewhere in a vicinity of the critical point of the VDW system.
Large values of $\eta/s\gg 1$ are, however, found in both the low-density,
$n\ll n^{}_0$, and high-density, $n>2n^{}_0$, regions. This makes the ideal
hydrodynamic approach inapplicable for these densities.
