Puerperal insanity, or what might be understood as a form of postnatal depression, was the third most frequent diagnosis among the women of the Fremantle Lunatic Asylum from 1858 to 1908. The emphasis society placed on pregnancy and child-rearing as women's primary function resulted in anxieties surrounding childbirth. Modern medical professionals are now aware there are several factors involved in postnatal depression. However, nineteenth-century physicians viewed it as a common issue of 'mental derangement' in women soon after childbirth, but unlikely to be permanent. To treat this, Fremantle Asylum physicians instituted moral treatment methods, including domestic work as rehabilitation. As this paper demonstrates, this form of rehabilitation reinforced the conventional feminine behaviours essential for functioning wives and mothers in nineteenth-and early twentieth-century society. As women suffering puerperal insanity challenged the notions of domesticity and femininity, their experiences allow for an analysis of how moral treatment was implemented in Fremantle. Through the patient records and case books of the Fremantle Asylum, this paper reveals that moral treatment did not cure all patients, leaving some susceptible to readmission and continued mental illness.