This article explores the legal and clinical processes underpinning gender differences in Australian Family Court statistics which show that mental illness is the primary reason for limiting mothers’ contact with their children. Analysis of a sample of published judgments from 2009 to 2011 featuring mental illness and outcomes of limited child contact identified that allegations of child sex abuse were a common feature of cases in which mothers’ child contact was limited. Four illustrative cases are presented with a focus on the processes used in the identification of mental illness. The data indicate that there are different patterns of response to cases where a party has a previously diagnosed mental illness and cases where mental illness is invoked as a possible explanation for child sex abuse allegations. These identified patterns of differentiated response provide a possible explanation for the gender disparity in Family Court reasons for limiting child contact on the grounds of mental illness.