Although previous research indicates that both employment and adult attachment style have an influence on academic achievement, the interaction of these two factors has not been clarified. The purpose of this study was to investigate the moderating effect of adult attachment style on the relationship between employment status and first semester academic achievement in higher education. A sample of 378 freshman college students answered a series of questionnaires (Academic Amotivation Inventory, the Relationship Questionnaire and demographic), and their high school averages and first semester academic results were obtained from the Registrar's office. The Analysis of covariance showed that employment status (having employment vs. no employment) and adult attachment style of students (secure vs. dismissing) strongly interacted in predicting academic achievement (first semester average adjusted for high school average, perceived financial burden, and amotivation). More specifically, the first semester averages of secure students with or without employment, and that of dismissing students without employment was indistinguishable. However, dismissing students with employment had significantly lower first semester averages than the secure students. This study showed that dismissing students entering postsecondary education who also have employment are at greater risk of academic difficulties than students with a secure attachment style.