The structures, the harmonic frequencies, and the energies of Fe(H2O)(n)(imid)(m)(2+) and Ni(H2O)n(imid)(m)(2+) complexes are computed using density functional theory with the B3LYP functional. A CSOV analysis shows that the bonding is mostly electrostatic in nature. Imidazole forms a stronger bond than water with both metal dications because of its larger dipole moment and polarizability. The reactions for the exchange of one water molecule by one imidazole are exothermic, and up to six water molecules can be replaced by imidazoles. The trends are very similar for both metals with the displacement reactions being slightly more favorable for Ni2+.