Service engagement continues to challenge providers working with individuals with serious mental illness and substance abuse disorders. Motivational Interviewing (MI), an intervention aligned with recovery-oriented principles in its emphasis on empathy, empowerment, and self-directed change, directly addresses this problem. Its effects on service engagement, however, have been inconsistent with dually diagnosed populations. To explore underlying processes that may influence engagement, the present mixed methods, single case experiment studied the effects of MI on key recovery constructs: hope, meaning, and empowerment. Participants were 6 consumers enrolled in an intensive outpatient program for co-occurring disorders. Results showed statistically significant increases for half the sample on a brief hope, meaning, and empowerment survey. Grounded theory analysis also identified positive change in identity, self-efficacy, and relationships as major recovery themes discussed in MI. It also revealed positive affect associated with spirit and method of MI. Implications for attention to personal narratives, supporting persistence in change, and satisfying psychological needs proposed by self-determination theory (SDT) are discussed.