The English National Health Service (NHS) started to implement reforms in 2016 to create a culture of openness, transparency, and accountability across the entire hospital system. However, there is a debate among policy makers and researchers about whether and to what extent openness is related to significant improvements in health system performance or lower mortality rates. Drawing on data from 137 English acute trusts (or hospital systems) for the period 2012–14, we used multivariate regression models to test whether mortality rates, taken from the Summary Hospital-level Mortality Indicator, were lower in hospitals that had higher levels of openness among staff members, a measure derived from the NHS National Staff Survey. When we adjusted for hospital operating capacity, our results showed that a one-point increase in the standardized openness score was associated with a 6.48 percent reduction in hospital mortality rates. These findings have important policy implications: They offer empirical evidence to support further efforts to increase openness in the English hospital system, since doing so has improved health care quality.