► Coverage by nighttime GDL at fatal crash was 90.1% of 15-year-olds, 84.4% of 16-year-olds and 29.5% of 17-year-olds. ► Total non-compliance with nighttime GDL laws was 14.9% at time of fatal motor vehicle crash. ► Nighttime non-compliance was 18.8% for crashes in which the driver died. ► Over one half of all nighttime GDL non-compliant crashes took place on Friday and Saturday nights. ► The new social definition of the weekend captured a 10% higher mortality rate compared to traditional weekend definitions. Examination of teen driver compliance with graduated driver licensing (GDL) laws could be instrumental in identifying factors associated with persistently high motor vehicle mortality rates. Fatality analysis reporting system (FARS) data from the years 2006 to 2009 were used in this nation-wide cross-sectional study of drivers covered by a state nighttime GDL law (n=3492). A new definition of weekend, based on the school night in relation to the teenage social landscape, redefined Friday night as a weekend night and Sunday night as a weekday/school night and compared it to previous weekend definitions. Multiple logistic regression was used to examine independent effects of demographic, behavioral, environmental, contextual, and other factors on compliance with nighttime GDL laws. All analyses were performed in Stata version 11. Given coverage under nighttime GDL laws, drivers aged 15–17 years were non-compliant in 14.9% of the fatal MVCs in which they were involved, and nearly one-fifth (18.8%) of all fatalities aged 15–17 years were associated with non-compliance. Mortality risk was 10% higher using a revised social (school night) versus traditional (Sat–Sun) weekend definitions. In multivariable analysis, drivers non-compliant with nighttime GDL laws were more likely to be drinking (OR=4.97, 3.85–6.40), unbelted (OR=1.58, 1.25–1.99), driving on the weekend (OR=1.82, 1.47–2.24), and killed (OR=1.31, 1.04–1.65). GDL non-compliance contributes to teen motor vehicle mortality. Legislative and enforcement efforts targeting non-school night driving, seatbelt nonuse and alcohol have potential to further reduce teen driving mortality.