  Perturbative QCD results on pion production are presented in proton-proton,
proton-nucleus and nucleus-nucleus collisions from CERN SPS up to RHIC energy.
A K_{jet}(s, p_T, Q) factor obtained from jet production is applied to perform
next-to-leading order calculations. Using the intrinsic transverse momentum
(k_T) we determined transverse momentum spectra for pions in wide energy
region. We have investigated nuclear multiscattering and the Cronin effect at
RHIC energies.
