  We discuss the results of calculations of the shear viscosity and thermal
conductivity of pure neutron matter, carried out within the
Landau-Abrikosov-Khalatnikov formalism. The probability of neutron-neutron
collisions in the nuclear medium has been obtained from a realistic potential,
using both the correlated basis function and the $G$-matrix approach. The
results of our work indicate that medium modifications of nucleon-nucleon
scattering are large, their inclusion leading to a dramatic enhancement of the
transport coefficients. On the other hand, the results obtained from the two
theoretical schemes appear to be in fairly good agreement.
