Ancient Greek descriptions of ecstatic and mystic rituals, here broadly labeled as Bacchantic worship, regularly include elements of moral corruption and dissolution of social unity. Suspicions were mostly directed against unofficial cult groups that exploited Dionysiac experiences in secluded settings. As the introduction of copious new cults attests, Greek religion was receptive to external influences. This basic openness, however, was not synonymous with tolerance, and pious respect for all deities did not automatically include their worshippers. This article reconsiders the current view of ancient religious intolerance by regarding these negative stereotypes as expressions of prejudice and by investigating the social dynamics behind them. Prejudices against private Bacchantic groups are regarded as part of the process of buttressing the religious authority of certain elite quarters in situations where they perceive that their position is being threatened by rival claims. It is suggested that both the accentuation and alleviation of prejudice is best understood in relation to the relative stability of the elite and the religious control it exerted.