Currently, studies exploring the relationship between treatment expectations (TE) and outcome among individuals with substance use problems are significantly lacking. This is important as relapse and attrition rates among this group are greater than those with other psychological problems. Understanding how TE impact treatment outcomes among this group would provide information to clinicians about which TE to intervene in order to positively influence treatment outcomes. Thus, this eight-month follow-up study investigated TE that could predict treatment outcomes (i.e., clients' substance use, mood states, number of treatment sessions received and clients' satisfaction with the service they received) among 130 outpatients with substance use problems. Using binary logistic regression, age, gender and TE were entered as predictors of treatment outcomes. Results showed that those that had higher expectations about taking responsibility and being open in counseling were more likely to report improvements in their main substance of concern. Furthermore, those that had higher expectations for a positive outcome from counseling were more likely to improve their mood especially depression levels. Although TE could not predict attrition, younger clients were more likely to leave treatment without notice or against advice, receive less treatment sessions and be less satisfied with the treatment they received. Individuals that had higher expectations of being open in counseling and for clinicians' to self-disclosure were more likely to be satisfied with the treatment they received. The findings not only have clinical implications but also implications in relation to developing policies for clinicians working with clients with substance use problems as well as conducting further research in this area.