  We present predictions for the total cross section for the production of a
charged Higgs boson in the intermediate-mass range ($m_{H^{\pm}}\sim m_t$) at
the LHC, focusing on a type-II two-Higgs-doublet model. Results are obtained at
next-to-leading order (NLO) accuracy in QCD perturbation theory, by studying
the full process $pp\to H^\pm W^\mp b \bar b$ in the complex-(top)-mass scheme
with massive bottom quarks. Compared to lowest-order predictions, NLO
corrections have a sizeable impact: they increase the cross section by roughly
50\% and reduce uncertainties due to scale variations by more than a factor of
two. Our computation reliably interpolates between the low- and high-mass
regime. Our results provide the first NLO prediction for charged Higgs
production in the intermediate-mass range and therefore allow to have NLO
accurate predictions in the full $m_{H^{\pm}}$ range. The extension of our
results to different realisations of the two-Higgs-doublet model or to the
supersymmetric case is also discussed.
