This paper provides evidence suggesting that gun control measures have been effective in reducing the toll of violence on population health in Brazil. In 2004, for the first time in more than a decade, firearm-related mortality declined 8 percent from the previous year. Firearm-related hospitalizations also reversed a historical trend that year by decreasing 4.6 percent from 2003 levels. These changes corresponded with anti-gun legislation passed in late 2003 and disarmament campaigns undertaken throughout the country since mid-2004. The estimated impact of these measures, if they prove causal, could be as much as 5,563 firearm-related deaths averted in 2004 alone.