The authors examined the relationship between nurse working conditions and nursing unit costs in 210 general medical, general surgical, and general medical surgical units in 112 randomly selected U.S. hospitals. Data were collected from registered nurses ( N = 3,747 and 2,878), patients ( N = 2,100), study coordinators, and secondary data sources. After controlling for relevant hospital, nursing unit, and patient characteristics, the authors found that good working conditions did not increase nursing unit costs. Teaching status was associated with higher costs, whereas larger unit size was associated with lower costs. Higher proportions of registered nurses and licensed practical nurse staffing were also associated with higher costs. Patient variables were not significantly related to costs. We suggest a variety of strategies that managers may use to improve working conditions.