High-level ab initio calculations, employing a range of theoretical methods up to RCCSD(T), together with effective core potentials and large valence basis sets, have been used to calculate the geometry and harmonic vibrational frequencies of RbOH, CsOH, FrOH, and the corresponding cations. It is concluded that although fairly good agreement with the M-O stretch frequency is obtained, there is likely to have been a misassignment of the bending vibration in previous infrared studies of RbOH and CsOH. Also, despite excellent consistency among the calculated results, there are discrepancies with previously reported equilibrium bond lengths. The adiabatic ionization energies of RbOH, CsOH, and FrOH are reported, together with the dissociation energies of the neutrals and the cations. It is concluded that the cations have a (2)Pi ground state.