The National Highway Traffic Safety Administration says seat belt usage in Mississippi was 63.2 percent, the lowest in the country. The national average was 80 percent. Figures were calculated using state data.
Massachusetts was at 63.3 percent and Arkansas was at 64.2 percent.
Arizona and Hawaii beat the national average with 95 percent seat belt usage.
Warren Strain, spokesman for the state Department of Public Safety, said Mississippi has not had much of a change in four years.
In 2000, the state was one of the first to carry out the federal campaign titled "Click it or Ticket," which includes two weeks of enforcement and two weeks of advertisement.
Seat belt usage jumped 12 percent to 62 percent from 50 in 2001, but Strain says it hasn't improved that much since the big jump.