A computer-aided campaign boosted the discovery of potent human neutrophil elastase (HNE) inhibitors. A pharmacophoric model was developed, validated and applied to filter an oxo-beta-lactam library previously generated by de novo design. This campaign led us to compound 1 which showed an inhibitory activity of 6.9 nM against HNE, more active than the only commercially available HNE inhibitor for therapeutic usage. Computer-aided methodologies proved again to be powerful tools to increase the rate of success for HNE inhibitor discovery either for therapeutic or activity-based probing development.