Pretreatment changes in alcohol use challenges the assumption that the major portion of the change process occurs after treatment entry. Greater understanding of the behavior change process prior to treatment has the potential to improve our understanding of behavioral changes during treatment. In this study, participants (N = 45) were recruited for a clinical trial examining multiple mechanisms of change in cognitive-behavioral treatment for alcohol dependence. Using data from both baseline and end of treatment assessments, several pretreatment intervals were created (e.g., a two-week pre-phone call interval, phone call to baseline assessment, baseline assessment to first treatment). To examine pretreatment changes in drinking, percent days abstinent and drinks per drinking day were analyzed using multi-level growth curve modeling and repeated measures ANOVAs. Initial examination of the data revealed significant increases in percent days abstinent and decreases in drinks per drinking day during the pretreatment intervals. Follow-up analyses also suggested that the majority of change in drinking occurs between the phone call and baseline assessment. Further examination of the data revealed two distinct patterns of pretreatment change: a) rapid changers who maintained changes during the course of treatment, and b) gradual changers who changed more gradually during the course of treatment. Analyses revealed that rapid changers had significantly higher rates of abstinence and lower drinks per drinking day at 90 days post-treatment compared to gradual changers. Overall, the data suggest that a more systematic investigation of pretreatment changes in alcohol use is warranted. Future studies may yield insights resulting in more efficient treatment delivery and adaptations to treatment based on an individual's pretreatment change status. Changes in addictive behavior frequently take place without professional treatment (Sobell et al., 1991). Indeed, unaided change may be more common than professionally-aided change in the case of alcohol problems (Sobell et al., 1996). Even among those who enter treatment, there is much in their accounts to suggest that a large component of the change process is self-directed (Orford et al., 2006a), with a few studies showing that significant changes in drinking occur prior to the first formal treatment session (e.g., Epstein et al., 2005; Sobell, 2011). As Orford (2006a) notes, these findings suggest that formal treatments are embedded within a much larger system of change-promoting elements occurring before, during, and after formal treatment. Furthermore, these data challenge the assumption that the majority of change occurs after treatment entry and suggests that behavior change must be examined through a broader lens (Willenbring, 2007). Although there is a wealth of research on behavioral change during and after treatment for alcohol use disorders, few studies have focused on pretreatment change, or change that occurs prior to the first formal treatment session. The aim o...