The structures of the benzyl alcohol and its hydrogen-bonded clusters with water have been investigated by infrared-ultraviolet double resonance vibrational spectroscopy along with ab initio molecular-orbital calculations. Characteristic shifts of the OH stretching vibrations of the benzyl alcohol site as well as the water sites were found, which are quite useful to determine the cluster structures. For bare benzyl alcohol, a planar conformer having no intramolecular hydrogen bond is dominant in the jet. On the other hand, the dominant species becomes a gauche-type conformer in the benzyl alcohol-(H2O)(n) (n = 1-4) hydrogen-bonded clusters. In these clusters, the pi-hydrogen bond between the phenyl plane and the OH group of the water cluster site is possible. Detailed intermolecular hydrogen bonding structures are discussed by comparing the observed spectra with the simulated spectra obtained by ab initio calculations.