The purpose of this study was to determine if organizational, administrative, and practice factors differentiate among hospitals and patient care units as to registered nurse vacancy, stability, and turnover rates. Data from 90 patient care units in 15 hospitals are reported. Results from stepwise multiple regression indicate that 52% of the variability in vacancy, 56% of the variance in registered nurse stability, and 42% of the variance in relative turnover rates were explained by seven variables. Important predictors included nursing workload, characteristics of nurse staffing and practice, as well as job satisfaction. These findings indicate that a combination of organizational attributes and staff attitudes are important for understanding nurse staffing.