Cognitive behavioral therapy (CBT) has been found to be effective in preventing suicide-related behavior. However, it is often difficult to engage patients who are at-risk in treatment. Motivational Interviewing (MI) has been shown to increase treatment engagement and improve treatment outcomes when it is used to complement other treatments. As a general theory of human motivation that is consistent with MI, Self-Determination Theory (SDT) provides a framework for understanding how MI may be integrated with CBT to increase treatment engagement and outcome. In this paper, we use SDT to explain how MI may complement CBT to reduce suicide-related behavior, provide a case example of using MI with a suicidal patient before CBT-based treatment, and explore future directions for research.