International research suggests that problematic approaches and attacks on politicians are frequently perpetrated by individuals with severe mental illness who are either unknown to mental health services or who have disengaged from care. The current study investigated the extent of harassing behaviours towards Queensland State Parliamentarians and of perceived mental illness in their harassers. An anonymous survey was sent to all 89 Queensland Members of Parliament exploring a range of harassment behaviours. Responses were received from 48% of parliamentarians, 93% of whom reported at least one form of harassment. The most common intrusions were alarming behaviour at the electoral office and inappropriate correspondence or telephone calls, but threats to harm and attempted or actual physical assault were also reported. Almost half the perpetrators were thought to be mentally ill. These findings support a role for mental health intervention in managing risk to politicians and catalysing care for those who pursue them.