The refinement of our original five point pharmacophore model for the H(3) receptor with the addition of a new acceptor feature is presented. The importance of this new acceptor feature for the binding and the selectivity against H(1), H(2) and H(4) has been validated using a newly synthesized naphthalene series. With the SAR deduced from several hundred naphthalene derivatives in various sub-classes the specific role of each pharmacophoric feature, by varying the geometry, size and charge of the molecules, was elucidated. This led to the discovery of a highly potent and selective new compounds series.