Abstract
The process of charged Higgs production in association with a top quark atthe LHC has been calculated at the complete NLO electroweak level both in a TwoHiggs Doublets Model and in the Minimal Supersymmetric Standard Model, assuminga mSUGRA breaking scheme. We have numerically explored the size of the one-loopcorrections in two typical supersymmetric scenarios, with particular attentionto the tan beta dependence, and we have found that they remain perturbativelysmall but possibly sizable, reaching a 20% limit for extreme values of tanbeta, when the complete set of Feynman diagrams is taken into account.