This chapter provides a synthesis of the empirical literature that assesses the relationship between ready access to highly lethal means of suicide and overall suicide rates. It lays out the theoretical underpinnings of the assertion that reducing access to lethal means of suicide can reduce suicide rates. The most convincing evidence that restricting access to highly toxic pesticides saves lives comes from a series of papers by researchers who have been working to prevent suicide in Sri Lanka, where pesticides are the leading suicide method. The striking success in preventing suicides in Sri Lanka by reducing access to the most highly toxic pesticides is one of the strongest empirical arguments that suicide rates can be substantially reduced without necessarily targeting underlying mental health or suicidality. Household firearm ownership has been consistently found to be a strong predictor of suicide risk in studies that examined individual-level data.