As part of a larger investigation of the adverse effects of mental disorders on role functioning, we examined the associations of early-onset mental disorders with subsequent educational attainment in a large nationally representative survey of the US adult population. Diagnoses and age of onset for each of 17 DSM-IV disorders were assessed through retrospective self-report with the fully structured WHO Composite International Diagnostic Instrument (CIDI). Survival analysis was used to examine the associations between early-onset DSM-IV/CIDI disorders and subsequent termination of schooling with controls for socio-demographic characteristics and childhood adversities (i.e. childhood traumatic events, childhood neglect, parental mental illness, family disruption, and low parental educational attainment). Mental disorders were found to be significantly associated with termination of schooling prior to completion of each of four educational milestones (primary school graduation, high school graduation, college entry, college graduation), with odds ratios in the range of 1.3-7.0. The proportion of school terminations attributable to mental disorders was largest for high school graduation (10.2%) but also meaningful for primary school graduation (3.8%), college entry (4.4%) and college graduation (2.6%). These results add to a growing body of evidence documenting a wide variety of adverse life course effects of mental disorders.