Self-regulation refers to the ability to inhibit the automatic response and to do something else; more generally, it refers to the ability to control one's emotions, to control attention and other cognitive processes, and to plan and control behavior. This capacity turns out to have enormous consequences for academic and social success. And, as teachers observe daily, children differ widely in how much of this capacity they seem to have. Recent research indicates that teachers can help students--especially students having the most trouble--by providing an organized classroom environment, and by removing elements in the environment that can trigger impulsive behavior. Helping students better self-regulate is a daunting task because it seems such a personal, permanent quality of an individual. But researchers have shown that it is open to change, and they also have shown that good self-regulation is associated with a broad spectrum of positive academic and social outcomes, and that poor self-regulation is associated with greater risk for correspondingly bad outcomes. These facts highlight the urgency for teachers to do all they can to help students grow in this area. (Contains 49 endnotes.)