  The Run-1 of the LHC was very successful for single top physics. The main
single top production mode, $t-$channel, is now well established. The
$t-$channel cross-section was measured with unprecedented precision and
$t-$channel events have been used for the first time to perform measurements of
standard model properties, such as: $|V_{tb}|$, top quark polarization, or
$W$-helicity fractions. The associated production with a $W$ boson, $tW$, has a
large cross section at the LHC and has been observed by CMS for the first time.
Finally, the $s-$channel also has been studied and limits set on its production
cross section. Single top results produced by the CMS experiment at 7 and 8 TeV
are presented in the following.
