A. Aslanyan and E. B. Davies On eigenfunction approximations for typical non-self-adjoint Schroedinger operators (245K, gzipped ps) ABSTRACT. We construct efficient approximations for the eigenfunctions of non-self-adjoint Schroedinger operators in one dimension. The same ideas also apply to the study of resonances of self-adjoint Schroedinger operators which have dilation analytic potentials. In spite of the fact that such eigenfunctions can have surprisingly complicated structures with multiple local maxima, we show that a suitable adaptation of the JWKB method is able to provide accurate global approximations to them.