IntroductionSubstance use disorder (SUD) is often considered a chronic illness in which prolonged recovery, in terms of abstinence, is uncommon. Personality has been found to predict recovery, but not much is known about its long-term predictive ability as the majority of previous studies have had short follow-up periods (≥ one year). The current longitudinal cohort study therefore investigated whether personality traits predict short- (STR) as well as long-term recovery (LTR) in SUD patients. MethodsTreatment-seeking patients with SUD (n = 123) completed the NEO Personality Inventory – Revised. STR and LTR categories were defined as scoring <8 on the Alcohol Use Disorders Identification Test – C and <2 on the Drug Use Disorder Identification Test – C at the one-year and 6–8-year follow-up, respectively. Whether personality traits predicted outcome was investigated by two-tailed independent samples t-tests, α < 0.05. Additional analysis was conducted with latent growth curve model. ResultsNeuroticism (inversely, p = .004, d = 0.55) and Extraversion (p = .04, d = 0.38) predicted STR (n = 114). Although not significant the effect size for Conscientiousness was above the cut-off for a practical significant effect (d = 0.31). No traits predicted LTR category. Still, the effect sizes for LTR regarding Neuroticism (d = 0.36), Extraversion (d = 0.21) and Conscientiousness (d = 0.27) indicated that these traits have relevance for LTR. The latent growth curve model indicated that these traits predicted the short-term use of drugs and long-term use of alcohol in this cohort dominated by patients suffering from severe poly-SUD. ConclusionPersonality traits predict recovery. The effect sizes indicate that more studies with larger samples on personality traits and LTR are required to understand their possible influences on the recovery process.