The (H2O)(n) and benzene-(H2O), (n = 1-3) clusters have been characterized by means of the MP2 and density functional methods. The minimum-energy structures were optimized, and the harmonic frequencies were calculated for both the benzene-water clusters (BWn) and the free water clusters (W-n). The W-n clusters are pi-hydrogen-bonded to the benzene ring, with the strength of this interaction being greatest for BW2. The geometries of the W-n portions of the BWn clusters are found to be close to those of the free water clusters, with the perturbation due to the interaction with the benzene being greatest for BW3. For the OH stretching modes good agreement is found between the calculated and measured OH stretch IR spectra for both W-n and BWn clusters. Both geometric and electronic (i.e., charge transfer/polarization interactions) effects are responsible for the significant changes in the OH stretch IR spectra brought about by the complexation of the water clusters with the benzene molecule.