BACKGROUND: Attention-deficit hyperactivity disorder (ADHD) has been associated with socioeconomic difficulties later in life. Little research in this area has been based on longitudinal and community studies. AIMS: To examine the relationship between childhood attention problems and socioeconomic status 18 years later. METHOD: Using a French community sample of 1103 youths followed from 1991 to 2009, we tested associations between childhood attention problems and socioeconomic status between ages 22 and 35 years, adjusting for potential childhood and family confounders. RESULTS: Individuals with high levels of childhood attention problems were three times more likely to experience subsequent socioeconomic disadvantage than those with low levels of attention problems (odds ratio 3.44, 95% CI 1.72-6.92). This association remained statistically significant even after adjusting for childhood externalising problems, low family income, parental divorce and parental alcohol problems. CONCLUSIONS: This longitudinal community-based study shows an association between childhood attention problems and socioeconomic disadvantage in adulthood. Taking into account ADHD and associated difficulties could help reduce the long-term socioeconomic burden of the disorder.