The properties of methanol clusters [(CH(3)OH)(n), n = 1-12] have been studied by using ab initio electronic structure calculations with reference to the aggregation number dependence of several reactivity descriptors, such as ionization potential, electron affinity, polarizability, hardness, and binding energy. A good correlation between the dipole polarizability and the ionization potential of these hydrogen-bonded molecular clusters is shown to exist. The softness parameter has also been shown to correlate strongly with the dipole polarizability of these molecular clusters. Similar good correlations are also demonstrated to exist for water clusters [(H(2)O)(n), n = 1-20]. This work can thus be useful for calculating the polarizability of larger methanol or water clusters in terms of the corresponding ionization potential.