The application of HASL (hypothetical active site lattice) methodology has been successfully extended to generate putative pharmacophoric patterns in three dimensions capable of quantitatively predicting binding activity. The transformation of a HASL model to a pharmacophore is illustrated using pKi values published for 84 HIV-1 protease inhibitors. Starting with a HASL model generated at 2.00 A and containing 899 lattice points, a selective trimming process was used to identify significant lattice points. In this manner, a set of 11 points was found which represents a potential pharmacophoric pattern and predicts the pKi activity of the 84-inhibitor set with a correlation (r2) of 0.827. Furthermore, the locations of these points were found to coincide with a number of strategic binding areas within the known active site structure HIV-1 protease, thus providing a physical confirmation of their relevancy.