Nurses are obliged to set professional boundaries in nurse-patient relationships. Relationships with patients that are pursued outside of working hours (dual relationships) are commonly prohibited by legislation and professional codes of ethics, but some nurses still engage in them. A thematic analysis of qualitative interviews revealed that the nurses experienced ambivalence regarding how they see the patients, their assessment of the dual relationships and how people around the nurses react to the relationships. Ambivalence was characterized by contradictory and indeterminate thoughts and attitudes toward patients and dual relationships. Results indicated that dual relationship decisions were complex and highly contextually dependent.