An up-to-date review of the nucleon-nucleon scattering situation is presented in the intermediate-energy region (100 MeV up to a few GeV). Total cross-section measurements are discussed, but the main emphasis is on the spin physics. Technical advances for polarized beams and targets are presented. The most recent spin-dependent NN data are reviewed and their influence in phase-shift analyses is discussed. The direct reconstruction of the scattering amplitudes is studied and results are compared to those obtained by phase-shift analyses. Finally future plans and expected improvements are detailed.