Abstract: Objective: To examine the relationships between nurse staffing levelwith quality of care and patients'outcomein intensive care unit (ICU). Methods: For this retrospective study, discharge data from 2013 to 2015 was obtained from a general ICU. Outcome measures include pressure ulcer prevalence rates, unplanned extubation, nursing adverse events, and ventilator-associatedpneumonia (VAP). The nurse staffing level was assessed by the number of patients assigned to a nurse. Linear probability model was used to assess the effects of nurse staffing on quality of care.Results:There were no statistical significances between nursing staffing level and pressure ulcers, unplanned extubation, VAP, central catheter related bloodstream infection (CRBSI) and nursing adverse events. A lower number of patients per nurse was significantly associated with a lower incidence of urinary tract infection.Conclusion: This study found that nurse staffing influence quality of nursing. The findings suggest that hospitals could promote nursing quality by improving nurse staffing.