Dementia guidelines recommend antipsychotics are only used for behavioral and psychological symptoms when non-drug interventions fail, and to regularly review use. Population-level clinical quality indicators (CQIs) for dementia care in permanent residential aged care (PRAC) typically monitor prevalence of antipsychotic use but not prolonged use. This study aimed to develop a CQI for antipsychotic use >90days and examine trends, associated factors, and variation in CQI incidence; and examine duration of the first episode of use among individuals with dementia accessing home care packages (HCPs) or PRAC. Retrospective cohort study, including older individuals with dementia who accessed HCPs (n=50,257) or PRAC (n=250,196). Trends in annual CQI incidence (2011-12 to 2015-16) and associated factors were determined using Poisson regression. Funnel plots examined geographical and facility variation. Time to antipsychotic discontinuation was estimated among new antipsychotic users accessing HCP (n=2367) and PRAC (n=15,597) using the cumulative incidence function. Between 2011-12 and 2015-16, antipsychotic use for >90days decreased in HCP recipients from 10.7% (95% CI 10.2-11.1) to 10.1% (95% CI 9.6-10.5, adjusted incidence rate ratio (aIRR) 0.97 (95% CI 0.95-0.98)), and in PRAC residents from 24.5% (95% CI 24.2-24.7) to 21.8% (95% CI 21.5-22.0, aIRR 0.97 (95% CI 0.96-0.98)). Prior antipsychotic use (both cohorts) and being male and greater socioeconomic disadvantage (PRAC cohort) were associated with higher CQI incidence. Little geographical/facility variation was observed. Median treatment duration in HCP and PRAC was 334 (interquartile range [IQR] 108-958) and 555 (IQR 197-1239) days, respectively. While small decreases in antipsychotic use >90days were observed between 2011-12 and 2015-16, findings suggest antipsychotic use among aged care recipients with dementia can be further minimized.