  We review current and new estimates of the eclipsing binary YZ Cassiopeiae
metallicity (Z). Since the individual components cover a quite large range of
mass (1.35-2.31 Solar masses), YZ Cas is potentially one of the best stellar
laboratories to understand the structure and evolution of 1 to 2 Solar masses
stars. The derivation of Z from IUE spectra, as well as from photometric
indices, provides the chemical composition of the atmosphere (Z_{atmospheric}),
while the fit of evolutionary tracks provides the initial chemical composition
(Z_{initial}). While a disagreement is expected between Z_{atmospheric} and
Z_{initial} because the primary component is an Am star (one expects
Z_{atmospheric} to be larger), we find some unexpected discrepancy between
atmospheric determinations of Z for this star.
