A group of agonists for the alpha7 neuronal nicotinic acetylcholine receptors (nAChRs) was investigated, and their free energies of binding DeltaG(bind) were calculated by applying the molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) approach. This method, based on molecular dynamics simulations of fully solvated protein-ligand complexes, allowed us to estimate the contribution of both polar and nonpolar terms as well as the entropy to the overall free energy of binding. The calculated results were in a good agreement with the experimentally determined DeltaG(bind) values, thereby pointing to the MM-PBSA protocol as a valuable computational tool for the rational design of specific agents targeting the neuronal alpha7 nAChR subtypes.