Objective: Findings from over a dozen studies of Hispanic/white disparities in seat belt use have been inconsistent, variably revealing that seat belt use prevalence among Hispanics is higher, lower, or comparable to use among non-Hispanics. In contrast to previous studies, this study investigates disparities in seat belt use by Hispanic subgroups of national origin. Methods: Data from the US Fatality Analysis Reporting System were used to compare seat belt use among 60 758 non-Hispanic whites and 6879 Hispanics (Mexican American (MA), n = 5175; Central American/ South American (CASA), n = 876; Puerto Rican (PR), n = 412; Cuban (CU), n = 416) killed in crashes from 1999-2003. Logistic regression was used to adjust for age, gender, seat belt law, seat position, urban/ rural region, and income. Results: Overall adjusted odds ratios for seat belt use among Hispanic subgroups, relative to non-Hispanic whites, were 1.04 (95% confidence interval (CI) 0.85 to 1.28) for CUs, 1.17 (95% CI 0.95 to 1.44) for PRs, 1.33 (95% CI 1.25 to 1.42) for MAs, and 1.66 (95% CI 1.44 to 1.91) for CASAs. Relative to their nonHispanic white counterparts, odds ratios among MA and CASA Hispanics were highest for men, younger age groups, drivers, primary law states, rural areas, and lower income quartiles. Conclusion: Among all Hispanic subgroups, seat belt use was at least as prevalent as among non-Hispanic whites. In the CASA and MA subgroups, which have the most rapidly growing subpopulations of immigrants, seat belt use was significantly more common than among whites.