The article reviews research on gun carrying and reports new findings from the National Self-Defense Survey on the prevalence, incidence, and patterns of adult gun carrying for protection. About 8.8 percent of adults carried guns in the preceding year, 3.7 percent carried guns on their person, and 6.5 percent carried guns in a vehicle. Within a given year, about 16.8 million U.S. adults carry a gun, 7.1 million who carry do so on the person and 12.4 million do so in a vehicle. On an average day, 2.7 million U.S. adults carry a gun for protection on their person and 5.0 million carry one in a vehicle. Less than one in a thousand instances of gun carrying involves a violent gun crime. Carrying was more common among males, Blacks, people in the South and West, people with a job requiring a gun, those who know someone who was recently the victim of a crime, believe that crime is above average in their neighborhood, have been a robbery victim, or believe people must depend on themselves for protection.