Substance use disorders (SUDs) are often comorbid with other psychopathology such as mood disorders, anxiety disorders, and personality disorders. While some research suggests individuals with comorbid psychopathology are more likely to seek substance use treatment than those with independent disorders, other studies have also shown many individuals with dual diagnoses still never seek treatment. Moreover, few studies have tried to elucidate the underlying structure of SUD treatment rejection, and instead examined it in more simplistic terms. In addition, studies have tended to examine the impact of individual disorders on treatment rejection, but have not incorporated an empirically supported approach to conceptualizing psychopathology in terms of comorbidity between broad latent dimensions referred to as internalizing (e.g., depression, anxiety) and externalizing (e.g., antisocial personality disorder, polysubstance use) psychopathology. Modeling psychopathology in terms of internalizing and externalizing psychopathology is becoming a prominent approach to understanding mental disorders, yet little research to date has investigated the effects these broad dimensions have on SUD treatment rejection. The current study utilized latent variable modeling techniques to (1) determine the latent structure of SUD treatment rejection in a large U.S. sample, and investigate whether treatment rejection is a multidimensional construct; and (2), to explore the ability of internalizing psychopathology, externalizing psychopathology, and personality pathology to predict the SUD treatment rejection factor(s). The current study relied on use of a general population sample of 43,093 individuals from the first wave of National Institute on Alcohol Abuse and Alcoholism's National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) study. Support was found for the hypothesis that SUD treatment rejection would be a multidimensional construct.  Exploratory structural equation modeling indicated a three-factor model best fit the data. Operational definitions and clinical implications of these three treatment rejection factors ("Objective barriers," "Psychological barriers," and "Self-focused barriers") are discussed. Among internalizing psychopathology, externalizing psychopathology, and personality pathology, structural equation modeling identified internalizing psychopathology as the most robust predictor of these three factors for alcohol treatment rejection (n = 1063), indicating endorsement of treatment barriers increased as levels of internalizing psychopathology increased. This pattern also held true for externalizing psychopathology, while personality pathology only negatively predicted objective treatment barriers.  For drug treatment rejection (n = 562), only internalizing psychopathology significantly predicted the treatment rejection factors, indicating treatment endorsement of drug treatment barriers increased as levels of internalizing psychopathology increased. Implications of these findings and directions for future research are discussed.