  We study the following nonlinear Choquard equation driven by a fractional
Laplacian: $$ (-\Delta)^{s}u+ u =(|x|^{-\mu}\ast
F(u))f(u)|{4.14mm}{in}|{1.14mm} \mathbb{R}^N, $$ with $N\geq3$, $s\in(0,1)$ and
$\mu\in(0,N)$. By Supposing that the nonlinearities satisfy the general
Berestycki-Lions type conditions \cite{BL}, we are able to prove the existence
of groundstates for this equation by variational methods.
