We examined whether mental state disorders (lifetime mood, anxiety, eating, substance misuse) with comorbid personality disorder are associated with physical multimorbidity in a population-based sample of women. Mental state and personality disorders were assessed using semi-structured diagnostic interviews. Clinical measures were performed and medical conditions, medication use and lifestyle factors were documented by questionnaire. Mental state disorders were associated with higher odds of physical multimorbidity; risk was especially high for those with comorbid personality disorder. These findings suggest that mental state and physical comorbidity might be worsened by the additional comorbidity of personality disorder.