School-shootings can enormously impact U.S. gun policy, but very little is known about the community mental health impact of school-shootings. We used difference-in-differences and event study analyses to compare stressrelated ED visits in zip-codes within 5 miles (exposed) and in zip-codes 10-15 miles from (control) school-shootings before and after school-shootings using data from California, 2005-2011. School-shootings and fatal schoolshootings were associated with annual increases of 0.7 and 1.5 stress-related ED visits per 1000 people, increases of 7% and 14%, respectively, compared to pre-shooting utilization. These previously unmeasured costs of schoolshootings reinforce calls to prevent gun violence, especially in schools.