The solvent reorganization energy of electron-transfer reactions is calculated for a solvent undergoing a structural phase transition from the isotropic to nematic phase. The calculation is based on the response function of the solvent polarization fluctuations obtained from Monte Carlo simulations of a model fluid of hard dipolar spherocylinders in a range of densities covering both the isotropic and nematic phases. The reorganization energy shows a significant anisotropy with respect to the orientation of the donor-acceptor complex relative to the nematic director in the nernatic phase. A possibility to control electron-transfer rates arising from solvation anisotropy is discussed.