No previous research has been published regarding the relationship between nurse staffing levels and inpatient pediatric falls, and previous research in the adult population has yielded conflicting results, probably due in many instances to suboptimal study design. The objective of this study was to examine the relationship between nurse staffing levels and pediatric patient falls in a large children's hospital. A case-control study design was used to compare the nurse staffing level during the shift of patient falls to the staffing level in the same units on shifts when patient falls did not occur. Nurse staffing levels were significantly lower in units when patient falls occurred, particularly during night shift. Targeted nurse staffing interventions in high-risk units could reduce the incidence of inpatient pediatric falls.