Insulin degrading enzyme (IDE) is a highly conserved zinc metalloprotease that is involved in the clearance of various physiologically peptides like amyloid-beta and insulin. This enzyme has been involved in the physiopathology of diabetes and Alzheimer's disease. We describe here a series of small molecules discovered by screening. Co-crystallization of the compounds with IDE revealed a binding both at the permanent exosite and at the discontinuous, conformational catalytic site. Preliminary structure-activity relationships are described. Selective inhibition of amyloid-beta degradation over insulin hydrolysis was possible. Neuroblastoma cells treated with the optimized compound display a dose-dependent increase in amyloid-beta levels.