The long-term stability of maladaptive personality traits in the general population has been under-investigated. The current study examined the longitudinal 20-year mean-level stability and rank-order consistency of five maladaptive personality traits-as measured with the Personality Psychopathology-5-r scales. Correlations and regression analysis were conducted to test both types of stability comparing raw scores of scale administrations in a general population sample in both 1992 and 2012 (N = 65). Repeated measures analysis of variance demonstrated significant mean-level stability of the PSY-5-r traits over 20 years. The PSY-5-r scales demonstrated significant rank-order consistency as evidenced by correlational analyses and reliability coefficients. The scales Aggressiveness-r (r = .73), Neuroticism/Negative Emotionality-r (r = .65), Introversion/Low Positive Emotionality-r (r = .63), and Disconstraint-r (r = .56), evidenced strong rank-order stability, whereas Psychoticism-r (r = .3) showed moderate rank-order consistency. The results of the present study indicate that maladaptive personality traits as measured with the PSY-5-r scales are relatively stable over 20 years in an adult community population.