This paper deals with the following Schrödinger–Poisson systems
−normalΔu+λV(x)u+νK(x)ϕ(x)u=a(x)f(u),1emx∈R3,−normalΔϕ=K(x)u2,1emu>0,1em1em1em1em1em1em1em1em1emx∈R3,
where λ, ν are positive parameters and V(x) is sign‐changing and may vanish at infinity. Under some suitable assumptions, the existence of positive ground state solutions is obtained by using variational methods. Our main results unify and improve the recent ones in the literatures. Copyright © 2016 John Wiley & Sons, Ltd.