AbstractAimTo examine the relationships among nurse staffing, nurses prioritization of nursing activities, missed care, quality of nursing care, and nurse outcomes.BackgroundInadequate staffing is associated with increased missed care, which threatens the quality of care and nurse outcomes.MethodsThe study sample included 2114 staff nurses from 156 medical or surgical units of 49 general hospitals who had participated in a cross‐sectional survey conducted in 2015. Nurse staffing was measured using the patient‐to‐nurse ratio and perceived staffing adequacy. The Missed Nursing Care Survey was used to measure how frequently nurses had missed each of 24 activities. Multilevel regression analyses were employed to examine the relationships among variables.ResultsThe prevalence of missed care differed by nursing activity. Poorer staffing was associated with an increased number of missed activities. A higher number of missed activities and poorer staffing were associated with poorer patient safety, quality of nursing care and job satisfaction, and a higher intent to leave. Nurses gave the highest priority to focused patient reassessments, timely medications, and patient teaching, under hypothetical conditions of improved staffing.ConclusionAdequate staffing is required to reduce missed care and to improve quality of care and nurse outcomes.