Spirituality or belief in a higher being is an integral part of Alcoholics Anonymous (AA). This study examines the role of religiosity in AA involvement and long-term sobriety in a representative sample of 587 men and women interviewed upon entering treatment and re-interviewed 1 and 3 years later. Religiosity is defined as spiritual, religious, secular (atheist or agnostic) and unsure, using the Religious Beliefs and Practices Scale employed in Project MATCH. Similar proportions within each religiosity group reported prior 12-month AA exposure at baseline; and over 40% of the unsure, spiritual and religious respondents and 25% of the secular respondents reported having gone to at least one AA meeting in the 12 months before the year 3 interview. Those who reported a spiritual awakening at year 3 were at the highest odds of continuous sobriety for the last year; notably, religious self-definition was not associated with a significantly higher odds of sobriety at year 3 after controlling for other considered influences. An increase in AA activities, other than AA meetings, between baseline and the year 1 follow-up was also associated with a higher odds of sobriety, highlighting the importance of increased AA involvement in the period immediately following treatment episodes.