Purpose of reviewThis article aims to examine the relationships between obsessive-compulsive disorder (OCD) and personality disturbance, with a particular focus on the diagnostic, aetiological and treatment implications of these relationships.Recent findingsPersonality disorders are common in OCD. They interact in various ways and in accordance with a number of the proposed models. The relationship between OCD and obsessive-compulsive personality disorder is the most important, but it can be conceptualised in different ways and may vary from one person to another. The most clinically relevant implication of the presence of schizotypal personality disorder in OCD is poor prognosis and treatment outcome of OCD. The findings of the effects of personality disorders on treatment outcome of OCD have been inconsistent for most personality disorders, largely due to poor quality of research. Better understanding of the specific relationships between OCD and personality disturbance should lead to a more tailored treatment approach.SummaryLarge prospective studies are needed to better understand how various relationships between OCD and specific personality disorders could be conceptualised more soundly. Such studies will also provide the foundation for more effective treatments of OCD patients with co-occurring personality disorders.