In this prospective study of psychiatric outpatients with personality disorders, the authors examined patient factors that predicted dropout from supportive-expressive (SE) psychotherapy. Eighty patients were randomized to 40 sessions of time-limited SE psychotherapy. The dropout rate was 35%; 50% of dropouts terminated psychotherapy before Session 7, and 10% were nonengagers. A model including age, type of Axis II cluster, total amount of interpersonal distress, and degree of focus on 1 particular type of interpersonal problem predicted 71% of the completers and 50% of the dropouts. The prediction model was more accurate for men than women. The findings regarding age and type of Axis II cluster are consistent with those of prior studies. The findings for total amount of interpersonal distress and degree of focus on 1 particular type of interpersonal problem are in accordance with key concepts in interpersonal theory and research. Thus, patients' manner of relating to others is associated with dropout. Researchers are encouraged to examine the association between interpersonal factors and dropout in greater depth.