The aim of this paper is to establish the existence of the first (smallest) eigenvalue \(\lambda _1\) for a nonlinear elliptic problem driven by the nonhomogeneous (p, q)-Laplace operator \(-\Delta _p -\Delta _q \) in a bounded domain with a source term involving the exponent \(\gamma \) with \(q<\gamma \le p\) . We show that \(\lambda _1\) is simple and associated to a unique and bounded eigenfunction \(u_1>0\) . In the second part, using variational arguments, we study two types of nonlinear problems involving the nonhomogeneous (p, q)-Laplace operator, in particular we study two classes of sublinear and superlinear (p, q)-Laplacian problems with parameters.