We study a semilinear elliptic equation of the form $$ - \Delta u + u = f(x,u), u \in H_0^1 (\Omega ),$$ where$f$is continuous, odd in$u$and satisfies some (subcritical) growth conditions. The domain Ω⊂R^{N}is supposed to be an unbounded domain ($N$≥3). We introduce a class of domains, called strongly asymptotically contractive, and show that for such domains Ω, the equation has infinitely many solutions.