Objectives: To estimate the number of deaths and the cost of deaths attributable to wood heater smoke in the Australian Capital Territory., Study Design: Rapid health impact assessment, based on fine particulate matter (PM 2.5 ) data from three outdoor air pollution monitors and published exposure-response functions for natural cause mortality attributed to PM 2.5 exposure., Setting: Australian Capital Territory (population, 2021: 454 000), 2016-2018, 2021, and 2022 (2019 and 2020 excluded because of the impact of extreme bushfires on air quality)., Main Outcome Measures: Proportion of PM 2.5 exposure attributable to wood heaters; numbers of deaths and associated cost of deaths (based on the value of statistical life: $5.3 million) attributable to wood heater smoke., Results: Wood heater emissions contributed an estimated 1.16-1.73 μg/m 3 to the annual mean PM 2.5 concentration during the three colder years (2017, 2018, 2021), or 17-25% of annual mean exposure, and 0.72 μg/m 3 (15%) or 0.89 μg/m 3 (13%) during the two milder years (2016, 2022). Using the most conservative exposure-response function, the estimated annual number of deaths attributable to wood heater smoke was 17-26 during the colder three years and 11-15 deaths during the milder two years. Using the least conservative exposure-response function, an estimated 43-63 deaths per year (colder years) and 26-36 deaths per year (milder years) were attributable to wood heater smoke. The estimated annual equivalent cost of deaths was $57-136 million (most conservative exposure-response function) and $140-333 million (least conservative exposure-response function)., Conclusions: The estimated annual number of deaths in the ACT attributable to wood heater PM 2.5 pollution is similar to that attributed to the extreme smoke of the 2019-20 Black Summer bushfires. The number of wood heaters should be reduced by banning new installations and phasing out existing units in urban and suburban areas., (© 2023 The Authors. Medical Journal of Australia published by John Wiley & Sons Australia, Ltd on behalf of AMPCo Pty Ltd.)