Background A personality disorder diagnosis signals a negative prognosis for depressive and anxiety disorders, but the precise abnormal personality traits that determine the temporal course of internalizing psychopathology are unknown. In the present study, we examined prospective associations between abnormal personality traits and the onset and recurrence of internalizing disorders. Methods A sample of 371 young adults at high risk for internalizing problems completed the Schedule for Nonadaptive and Adaptive Personality‐Second Edition—a measure of 12 abnormal personality traits and three temperament dimensions (i.e., Negative Temperament, Positive Temperament, Disinhibition vs. Control)—and underwent annual diagnostic interviews over 4 years of follow‐up. Results In multivariate survival analyses, Negative Temperament was a robust predictor of both new onsets and recurrences of internalizing disorder. Further, the Dependency and Self‐Harm abnormal personality dimensions emerged as independent predictors of new onsets and recurrences, respectively, of internalizing disorders after statistically adjusting for variation in temperament. Conclusions Our findings suggest that abnormal personality traits and temperament dimensions have complementary effects on the trajectory of internalizing pathology during young adulthood. In assessment and treatment settings, targeting the abnormal personality and temperament dimensions with the greatest prognostic value stands to improve the early detection of enduring internalizing psychopathology.