The validity of self-reported seatbelt use among low belt use populations has not been evaluated directly, despite the importance of such data for estimating the effectiveness of community-wide interventions and compliance with state laws. To address this gap in knowledge 612 drivers were recruited from convenience stores located in 12 randomly generated zip code areas located in El Paso, TX. Self-reported seatbelt use was compared with observed seatbelt use in a single sample of participants. Both data sets were collected almost contemporaneously and no participant was aware of having their seatbelt use observed. Hispanic (n = 388) and white/non-Hispanic (n = 126) drivers over reported seatbelt use by 27 and 21%, respectively. These findings suggest that response bias within low belt use populations may be greater than suggested by state and national data.