Recent theoretical results on the production and decay of top quarks are
presented. The implications of the new experimental results from the
TEVATRON are briefly discussed. Predictions for the top quark decay
rate and distributions are described, including the influence of QCD and
electroweak radiative corrections.
Top production at an $e^+e^-$ collider is discussed with
emphasis towards the threshold region.
The polarization of top quarks in the threshold region
is calculated with techniques based on Green's functions for $S$ and
$P$ waves.