•Almost half of fatally injured drivers tested positive to alcohol or illegal drugs.•Alcohol was the most commonly detected substance, followed by Δ9-tetrahydrocannabinol and methylamphetamine.•Poly substance detection was common.•While alcohol related fatalities decreased across the time period, both Δ9-tetrahydrocannabinol and methylamphetamine related crashes increased.•Younger and less experienced drivers were not over-represented in the sample. The problem of impaired driving is well documented in the literature but is heavily dependent upon self-report studies and/or databases that do not include in-depth information about the contributing origins of fatalities. This study aimed to conduct an in-depth analysis of Coroner’s findings for all fatally injured drivers in the state of Queensland in order to explore the prevalence of alcohol and different types of illicit substances (including drug combinations) in fatal crash reports. A total of 701 Coroner’s reports related to drivers or controllers of vehicles involved in traffic related fatalities for the period of 2011–2015 were analysed, revealing 306 controllers (43.6%) were detected with either alcohol or illegal drugs (e.g., methylamphetamine, Δ9-tetrahydrocannabinol, cocaine or MDMA) Alcohol was the most commonly detected substance identified with 223 cases (72.9% of the drug and alcohol sample). Illicit drug detections totalled 147 cases (48% of the drug and alcohol sample) with Δ9-tetrahydrocannabinol the most commonly detected illicit substance (109 cases; 35.6% of the drug and alcohol sample) followed by methylamphetamine (total of 63 cases; 20.6% of the drug and alcohol sample). An important theme to emerge was the prevalence of polysubstance use among fatally injured drivers, not just for alcohol and one drug type, but also multiple drug combinations. Fatality trends revealed a decrease in both non-substance and alcohol-related fatalities across the study period. However, road fatalities where an illicit substance was detected increased by approximately 57%. Males were overrepresented as a proportion of total fatalities (82.4%) and there were no significant sex or age differences regarding illicit substance related deaths. Drivers of passenger vehicles were most commonly identified in the data (66.2%), but motorcycle operators were disproportionately represented (28.1% of the total controller sample compared to 4% of vehicle registrations in Queensland) This case study analysis of fatal crashes not only confirms the ongoing problem of alcohol and driving, but also illuminates the emerging (and escalating) issue of illicit substances detected in fatally injured drivers.