Stuttering is frequently associated with negative consequences which typically begin in early childhood. Despite this, no previous studies have investigated the presence of personality disorders among adults who stutter. Therefore, the aims of the present study were to screen for personality disorders among adults who stutter, and to compare these screening estimates with matched controls from a national population sample. Using a matched case-control design, participants were 94 adults seeking treatment for stuttering, 92 of whom completed the International Personality Disorders Examination Questionnaire (IPDEQ) as a first-stage screener, and 920 age- and gender-matched controls from the Australian National Survey of Mental Health and Well-Being (ANSMHWB). A conditional logistic regression model was used to estimate odds ratios for the primary outcome: first-stage presence of any personality disorder; as well as specific personality disorders. Based on first-stage screening, the presence of any personality disorder was significantly higher for adults in the stuttering group than matched controls, demonstrating almost threefold increased odds. This difference between groups remained significant for all specific personality disorders, with four- to sevenfold increased odds found for Dissocial, Anxious, Borderline, Dependent and Paranoid personality disorders, and two- to threefold increased odds found for Histrionic, Impulsive, Schizoid and Anankastic personality disorders. In conclusion, stuttering appears to be associated with a heightened risk for the development of personality disorders. These results highlight the need for research regarding the assessment and treatment of personality disorders among adults who stutter. Educational objectives: The reader will be able to: (1) describe the nature of personality disorders, including factors thought to contribute to their development; (2) identify some of the negative consequences associated with stuttering which may contribute to the development of personality disorders among adults who stutter; (3) describe the process involved in screening for personality disorders, including various methods of scoring; and (4) summarize findings regarding the first-stage presence of personality disorders among adults seeking speech treatment for stuttering in the present sample in comparison with age- and gender-matched controls from a national population sample.