Electronic stability control (ESC) is a vehicle safety system designed to keep vehicles moving in the direction commanded by the driver and thereby prevent loss-of-control crashes. Previous research has shown that ESC has been highly effective at reducing road departures related to loss of control. ESC is mandatory in all U.S. passenger vehicles manufactured from model year 2012 onward; by a 2014 estimate, ESC is in approximately one-third of passenger vehicles on the road. The proliferation of ESC may therefore alter benefit-to-cost ratios for roadside barriers. The objective of this analysis was to determine the effect of ESC on fatal crashes with roadside barriers. This objective was a first step toward determining whether ESC reduced the overall rate of crashes with roadside barriers and whether ESC had any effect on impact conditions or injury outcomes in barrier crashes. For cars, ESC reduced the odds of fatal crashes with roadside barriers by about 50% and reduced the odds of fatal rollovers that occurred in association with roadside barriers by about 45%. For light trucks and vans, ESC reduced barrier fatality odds by about 40% and barrier-associated rollover fatality odds by about 55%. By 2028, when an estimated 75% of passenger vehicles will have electronic stability control, ESC will have the potential to prevent about 410 out of an estimated 1,180 possible barrier-related fatalities per year. In the long term, once installed in every U.S. passenger vehicle, ESC could prevent about 550 of those same 1,180 possible barrier-related fatalities each year.