The purpose of this exploratory descriptive case study was to identify features of nurse-patient interactions (NPI) in the development of a nurse-patient relationship (NPR). Observations of interactions in a cancer treatment unit included 60 videotaped, sequential, naturally occurring NPIs involving one dyad over a 3-day period. A microanalysis of the interactions was conducted using qualitative ethological methods. The analysis focused on identifying important recurring behavioral clusters and characteristic patterns of behavior that comprised these clusters. Important features of NPIs in the development of an NPR were identified and described in detail. The active and complementary roles of both participants in this process and the contribution of social exchange, trust, and humor are highlighted. The findings illustrate the importance of continuity of nursing care if NPRs are to be used to their fullest extent to address complex patient care needs.