Abstract: Objective: Intractable nausea and vomiting, known as hyperemesis gravidarum (HG), are relatively common medical problems among pregnant women. Although there are some studies based on psychiatric symptom scales, the relationship between HG and psychiatric disorders, particularly anxiety and personality disorders, is unclear. In this study, we aimed to investigate whether there is a difference among women with and without HG with respect to frequency of mood, anxiety and personality disorders.Methods: The study sample was composed of 52 patients with HG and 90 control pregnant women. Mood and anxiety disorders were ascertained by means of the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). Personality disorders were assessed with the Structured Clinical Interview for DSM, Revised Third Edition, Personality Disorders (SCID-II).Results: The prevalence of any mood disorder and any anxiety disorder in women with HG was 15.4% and 36.5%, respectively. In addition, 19 (36.5%) of the patients with HG had at least one personality disorder. According to reports collected from the participants in the study, most of the mood or anxiety disorders occurred before the pregnancy in women with HG. The prevalence of major depression, generalized anxiety disorder, avoidant personality disorder and obsessive–compulsive personality disorder was significantly higher in women with HG compared to the control subjects.Conclusions: The results of the present study suggest that mood and anxiety disorders, and personality disturbances are frequently observed among women with HG and that there is a potential relationship between these psychiatric disorders and HG during pregnancy.