A study was undertaken in North Carolina to determine the characteristics of the minority of drivers who were not using seat belts following an extensive publicity/ enforcement campaign, which had increased statewide use to 80 percent. Vehicles and drivers whose seat belt use was observed at 49 sites were matched against Division of Motor Vehicles registration and driver history files for vehicle owners; data were available for 2,650 of the observed drivers, out of an original sample of 5,044, who were judged to be the owners of the observed vehicles. The results of this investigation indicate that nonuse of seat belts was associated with male gender; younger age (<35); older vehicles (pre-1985); vehicles other than cars, especially pickups; and poor driving records. Telephone survey information indicated that nonusers differed from users; nonusers were less likely to have health care coverage, more likely to acknowledge having consumed large amounts of alcohol in the past year, and more likely to have an arrest record. When asked about enforcement of the belt use law, many nonusers said that they would not respond to higher fines but they would respond to driver license points. To change the belt use behavior of this hardcore nonuser population, it may be necessary - as was done in Canada - to combine publicity/ enforcement campaigns with driver license points as a penalty for nonuse.