  We calculate the longitudinal contribution to the alignment polarization
$\Pl$ of quarks produced in $e^+e^-$ annihilation. In the Standard Model, the
longitudinal alignment polarization vanishes at the Born term level and thus
receives its first non-zero contribution from the $O(\as)$ tree graph process.
We provide analytical and numerical results for the longitudinal alignment
polarization of massless and massive quarks, in particular for the recently
discovered top quark.
