Background Voluntary assisted dying is lawful in Victoria in limited circumstances and commences in Western Australia in mid-2021. There is evidence that in rare cases, unlawful assisted dying practices occur in Australia. Aims To determine whether assisted dying practices occurred in Victoria in the 12 months prior to the commencement of the Voluntary Assisted Dying Act 2017 (Vic) ('VAD Act'), and to examine features of any identified cases. Methods Exploratory case series of adult patients in Victoria who died between May 2018 and 18 June 2019 as a result of medication administered with the primary intention of hastening death. Cases were identified from a self-administered survey about medical end-of-life decisions for adult patients, completed by Victorian specialists treating adults at the end of life. We examined reported use of medication with the primary intention of hastening the patient's death; characteristics of assisted dying cases, including doctors' classification of such practices. Results Nine cases met the inclusion criteria. Death did not occur immediately after providing medication with the intention of hastening death. In eight cases, it was framed as palliative or terminal sedation and/or continuous deep sedation. Most doctors used language that distanced their practices from assisted dying. Conclusions Unlawful assisted dying practices seem to have occurred in a small number of deaths in Victoria prior to commencement of the VAD Act. These practices typically occurred within the context of palliative or terminal sedation and may be difficult to distinguish from lawful palliative care practice. Some survey responses possibly reflect ambiguity in doctors' intentions when providing medication.