Objective: The aim of the study was to describe referral patterns of maternity inpatients to the consultation-liaison psychiatry (CLP) service at a large women's hospital in metropolitan Melbourne, Australia. Method: Clinicians recorded socio-demographic data, referring unit, consultee's reason for referral, psychiatric diagnosis made, and treatment provided for all maternity inpatients referred from 2004 to 2008. Results: Main reasons for referral were detection of depression, past psychiatric history, and concern regarding a woman's coping. Most common diagnoses were depression, substance use disorders and anxiety disorders. Many women referred for assessment while inpatients were initially seen in the antenatal period. Conclusions: Pregnant women referred to a CLP service present with a range of mental health problems, most often depression, anxiety and substance use disorders. Many of these problems are evident in and require intervention during the antenatal period as well as at the time of confinement. CLP services to maternity hospitals should be provided in the antenatal as well as the inpatient setting.