Objective: The purpose of this study was to compare effects of adverse childhood experiences and adverse adult experiences on recovery from serious mental illnesses. Methods: As part of a mixed-methods study of recovery from serious mental illnesses, we interviewed and administered questionnaires to 177 members of a not-for-profit health plan over a 2-year period. Participants had a diagnosis of bipolar disorder, affective psychosis, schizophrenia, or schizoaffective disorder. Data for analyses came from standardized self-reported measures; outcomes included recovery, functioning, quality of life, and psychiatric symptoms. Adverse events in childhood and adulthood were evaluated as predictors. Results: Child and adult exposures to adverse experiences were high, at 91% and 82%, respectively. Cumulative lifetime exposure to adverse experiences (childhood plus adult experiences) was 94%. In linear regression analyses, adverse adult experiences were more important predictors of outcomes than adverse childhood experiences. Adult experiences were associated with lower recovery scores, quality of life, mental and physical functioning and social functioning and greater psychiatric symptoms. Emotional neglect in adulthood was associated with lower recovery scores. Conclusions and Implications for Practice: Early and repeated exposure to adverse events was common in this sample of people with serious mental illnesses. Adverse adult experiences were stronger predictors of worse functioning and lower recovery levels than were childhood experiences. Focusing clinical attention on adult experiences of adverse or traumatic events may result in greater benefit than focusing on childhood experiences alone.