  We compute the leading logarithms electroweak contributions to gamma gamma to
f f(bar) processes in SM and MSSM. Several interesting properties are pointed
out, such as the importance of the angular dependent terms, of the Yukawa
terms, and especially of the $\tan^2\beta$ dependence in the SUSY
contributions. These properties are complementary to those found in e+e- to f
f(bar). These radiative correction effects should be largely observable at
future high energy gamma gamma colliders. Polarized beams would bring
interesting checks of the structure of the one loop corrections. We finally
discuss the need for two-loop calculations and resummation.
