The infrared spectrum of the benzene-water cation, C6H6+-H2O, was recorded in the O-H stretch region to obtain first experimental information about its geometry and interaction strength. The spectrum is consistent with a charge-dipole structure in which the oxygen atom of H2O approaches the C6H6+ cation in the aromatic plane. The dissociation energy estimated from the spectral shifts is D-0 approximate to 14 +/- 3 kcal/mol. The interaction in the C6H6+-H2O cation is rather different from the one in the neutral dimer, demonstrating the dramatic ionization-induced changes of the interaction between an aromatic hydrocarbon and a polar ligand.