  Spin effects in strong interaction high energy processes are subtle phenomena
which involve both short and long distance physics and test perturbative and
non perturbative aspects of QCD. Moreover, depending on quantities like
interferences between different amplitudes and relative phases, spin
observables always test a theory at a fundamental quantum mechanical level; it
is then no surprise that spin data are often difficult to accomodate within the
existing models. A report is made on the main issues and contributions
discussed in the parallel Session on the ``Strong interactions at high energy"
in this Conference.
