  We are interested in the problem of existence of soliton-like solutions for
the nonlinear Klein-Gordon equation. In particular we study some necessary and
sufficient conditions on the nonlinear term to obtain solitons of a given
charge. We remark that the conditions we consider can be easily verified.
Moreover we show that multiplicity of solitons of the same charge is guaranteed
by the "shape" of the nonlinear term for equations on $\R^{N}$, hence without
appealing to topological or geometrical properties of the domain.
