  We compute next-to-leading order QCD corrections to the process $gg\to ZH$.
In the effective-theory approach we confirm the results in the literature. We
consider top quark mass corrections via an asymptotic expansion and show that
there is a good convergence below the top quark threshold which describes
approximately {\num a quarter} of the total cross section. Our corrections are
implemented in the publicly available {\tt C++} program {\tt ggzh}.
