Previously, we found that the naturally occurring stilbene compound resveratrol (RES) could potentiate cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel activity. Because some wild-type CFTR activators also potentiate its mutant forms, we investigated effect of RES on the two most common forms of CF-related mutation (deltaF508 and G551D-CFTR). Cell-based fluorescence studies indicated that RES dose-dependently potentiated both deltaF508 and G551D mutant CFTR Cl- channel activities. Transepithelial Cl- currents were stimulated by RES in deltaF508 and G551D mutant CFTR-expressing FRT cells. Further excised inside-out patch-clamp measurements revealed that RES significantly induced the chloride current of deltaF508 and G551D mutant CFTRs by increasing the open time of the channels. In ex vivo studies, RES stimulated fluid secretion in mouse trachea by optical measurement of single gland secretion. These data suggested that RES is a potent deltaF508 and G551D mutant CFTR potentiator, and RES may present a novel class of therapeutic lead compounds in treating cystic fibrosis.