This chapter explores the critical process of assessing whether supportive therapy is the appropriate intervention for a given patient. It distinguishes between diagnosis and formulation, emphasizing the importance of a comprehensive assessment that goes beyond categorical labels to understand the individual’s psychological functioning. Key considerations include evaluating patient suitability, risk factors such as suicidality, and the capacity to tolerate a therapeutic process. The chapter also examines the role of the reality principle, emotional intelligence, and engagement capacity in determining the potential benefits of therapy. Additionally, it highlights the significance of external support systems, the therapist’s competency, and the value of longer assessment periods when necessary.