  We study CP violation in associated production of a charged Higgs boson and a
top quark at the LHC, $pp \to tH^\pm +X$. The asymmetry between the total cross
sections for $H^+$ and $H^-$ production at next-to-leading order in the MSSM is
calculated analytically and a detailed numerical analysis is performed.
Furthermore, subsequent decays of $H^\pm$ to $tb$ and $ \tau^\pm \nu_\tau$ are
considered. In the case with $H^\pm \to tb$ decay the asymmetry can go up to
$\sim$~12%.
