Despite the traumatic and fatal nature of motor neurone disease (MND) and the caring experiences being described as unrelenting, little is known about risk of psychiatric morbidity and Prolonged Grief Disorder (PGD) for family caregivers. Methods: A cross-sectional survey of caregivers bereaved in 2016-2018 was distributed by the five MND Associations in Australia (2019). Validated tools for PGD (PG-13), anxiety, depression, and family functioning were included. Multinomial logistic regression was used to compare the factors associated with grief.