This report describes the physician-parent-child encounter during an invasive medical procedure in a pediatric emergency department. Fifty children underwent venipuncture or intravenous cannulation performed by 22 physicians and 6 nurses. The median age of the children was 12 months. Parents remained with their children during 31 (62%) of the 50 procedures. Parents were more likely to stay if they had previously stayed when this child (P = .05) or another (P = .02) had undergone a procedure. Parental decision to stay was not related to parental age, gender, race, marital status, or level of education, nor to the residents' age, gender, or level of training. Only 43% of the parents who did stay were given that option by the residents, and of those who did not stay 37% reported that physicians asked them to leave. Nonverbal cues by the residents, such as pulling the curtain closed or turning their back toward parents, were noted in 58% of the encounters in which parents did not stay. The residents and nurses indicated that parents should stay with their child for the following procedures: laceration repair, 66%; venipuncture, 58%; intravenous cannulation, 48%; arterial blood sampling, 32%; suprapubic aspiration, 20%; and lumbar puncture, 14%. In the emergency room studied, it appears that for venipuncture and intravenous cannulation, the majority of parents stay with their children. Parental decision to stay or leave is frequently made without discussion with the physician.