Throughout his life, Augustine faced the charge that, despite his apparent conversion to the orthodox Christian faith of the Catholic Church, his thought nonetheless retained vestiges of his roughly ten-year sojourn with the Manichees. No one was more relentless in this accusation than Augustine's Pelagian nemesis of his twilight years, Julian of Eclanum. Throughout most of church history, Augustine's reputation was little troubled by these allegations of crypto-Manichaeism. However, over the last century or so, the charge has once again taken on life. This article begins with a brief orientation to some of the main philosophical and theological tenets of Manichaeism, with an emphasis on those elements that will be important for assessing the Augustine question. Next, the history of the accusation that the Christian Augustine remained, in important if unconscious ways, a crypto-Manichaean will be traced from the time of Augustine to the present. Finally, one methodological direction in which an eventual resolution to this long-standing question may lie will be considered.