Relativistic Thomas-Fermi calculations of asymmetric semi-infinite nuc
lear matter have been performed using some current parameter sets of t
he sigma - omega - rho model. Symmetric semi-infinite nuclear matter i
s also calculated in the Hartree approximation. We present and discuss
the results for various macroscopic coefficients with special emphasi
s on the surface-symmetry properties and compare them with values from
non-relativistic Skyrme calculations and from semi-empirical mass for
mulae.