Using American panel data from the National Educational Longitudinal Study of 1988 this paperinvestigates the effect of working during full-time education on attainment. In particular the focus ison students in the twelfth grade of high school. By employing a propensity score matching approachcombined with difference-in-difference methods we attempt to overcome problems of sample selectionand unobserved heterogeneity in order to estimate an unbiased effect of working during highschool. Results indicate that once such factors are controlled for, little to no effect on reading andmath scores are found. Neither do we find evidence of a negative impact for those who work longhours per week. We thus argue that working during schooling (twelfth grade) has little detrimentalimpact on grades per se.