Root cause analysis (RCA) has been a Joint Commission mandated tool for examining sentinel events since 1997. However, there is little objective data supporting its effectiveness. This cross-sectional study used the Veteran Affairs (VA) National Center for Patient Safety database to examine the relationship between RCA volume and Patient Safety Indicator (PSI) rates. Predictably, larger VA facilities performed more RCAs annually, and the number of RCAs was positively correlated with the development of strong actions intended to improve safety. Conversely, VA facilities that performed fewer than four RCAs per year had significantly higher rates of adverse events for three of the PSIs studied, all within the post-operative domain. The detailed steps for performing an RCA are described in an AHRQ WebM&M commentary.