Experimental and computational studies of the solvent dependence of the first molecular hyperpolarizability (beta) for two donor-bridge-acceptor chromophores (CLD-1 and YLD156) are presented. Hyper-Rayleigh scattering (HRS) measurements are performed with 1907 nm excitation in a series of solvents with dielectric constants ranging from similar to 2 (toluene) to similar to 36 (acetonitrile). For both chromophores an approximately 2-fold increase in beta is observed by HRS over this range of dielectric constants. Computational studies employing a polarized continuum model to represent the solvent are capable of reproducing this experimental result. The experimental and computational results are compared to the predictions of the widely employed two-state model (TSM) for beta Surprisingly, for the chromophores studied here the TSM predicts that beta should decrease with increasing dielectric constant over the range investigated. The results presented here demonstrate that the TSM provides neither a quantitative nor qualitative description of the solvent dependence of beta for CLD-1 and YLD156. The enhancement of beta with increased dielectric constant suggests that modification of the dielectric surrounding the chromophore is one path by which the performance of nonlinear optical devices employing these chromophores may be significantly enhanced.