  We report results from the experiment NA57 at CERN SPS on hyperon production
at midrapidity in Pb-Pb collisions at 158 $A$ GeV/$c$ and 40 $A$ GeV/$c$.
$\Lambda$, $\Xi$ and $\Omega$ yields are compared with those from the STAR
experiment at the higher energy of the BNL RHIC. $\Lambda$, $\Xi$, $\Omega$\
and preliminary $K_S^0$ transverse mass spectra are presented and interpreted
within the framework of a hydro-dynamical blast wave model.
