Proteases have been successfully targeted for the treatment of several diseases, including hypertension, type 2 diabetes, multiple myeloma, HIV and hepatitis C virus infections. Given the demonstrated pharmacological tractability of this enzyme family and the pressing need for novel drugs to combat antibiotic resistance, proteases have also attracted interest as antibacterial targets--particularly the widely conserved intracellular bacterial degradative proteases, which are often indispensable for normal bacterial growth or virulence. This Review summarizes the roles of the key prokaryotic degradative proteases, with a focus on the initial efforts and associated challenges in developing specific therapeutic modulators of these enzymes as novel classes of antibacterial drugs.