This study attempts to identify factors associated with greater aftercare participation for 367 adults who completed abstinence-based residential addiction treatment between 2004 and 2007 at Bellwood Health Services in Toronto, Canada. Pre-treatment substance use, number of days spent in residential treatment, motivation, treatment satisfaction, and demographics were used to determine which characteristics predicted greater aftercare participation. The duration of residential treatment and treatment satisfaction emerged as significant predictors of aftercare attendance. Regular aftercare attendance was associated with lower levels of substance use at 6-month follow-up. Results suggest that a longer duration of residential treatment can influence continuing care engagement and highlight the importance of initial treatment retention for long-term recovery.