Abstract Among the clinical inhibitors of poly(ADP-ribose) polymerases (PARPs) and the commonly used PARP research tool compounds, veliparib and niraparib were recently identified as the most selective inhibitors of PARP1 and PARP2. We characterized the potency of A-966492, a PARP inhibitor with a chemical structure similar to veliparib and niraparib, in in vitro inhibition experiments of six PARP family enzymes. We find that the selectivity of A-966492 for PARP1 and PARP2 is intermediate between veliparib and niraparib.