OBJECTIVE To investigate whether the safety culture of a hospital unit is associated with the ability to improve. DESIGN Qualitative investigation of safety culture on hospital units following a before-and-after trial on hand hygiene. SETTING VU University Medical Center, a tertiary-care hospital in the Netherlands. METHODS With support from hospital management, we implemented a hospital-wide program to improve compliance. Over 2 years, compliance was measured through direct observation, twice before, and 4 times after interventions. We analyzed changes in compliance from baseline, and selected units to evaluate safety culture using a positive deviance approach: the hospital unit with the highest hand hygiene compliance and 2 units that showed significant improvement (21% and 16%, respectively) were selected as high performing. Another 2 units showed no improvement and were selected as low performing. A blinded, independent observer conducted interviews with unit management, physicians, and nurses, based on the Hospital Survey on Patient Safety Culture. Safety culture was categorized as pathological (lowest level), reactive, bureaucratic, proactive, or generative (highest level). RESULTS Overall, 3 units showed a proactive or generative safety culture and 2 units had bureaucratic or pathological safety cultures. When comparing compliance and interview results, high-performing units showed high levels of safety culture, while low-performing units showed low levels of safety culture. CONCLUSIONS Safety culture is associated with the ability to improve hand hygiene. Interventions may not be effective when applied in units with low levels of safety culture. Although additional research is needed to corroborate our findings, the safety culture on a unit can benefit from enhancement strategies such as team-building exercises. Strengthening the safety culture before implementing interventions could aid improvement and prevent nonproductive interventions. Infect Control Hosp Epidemiol 2017;38:1277-1283.