Due to climate change, landscape fires account for an increasing proportion of air pollution emissions, and their impacts on primary and pharmaceutical care are little understood. OBJECTIVES: To evaluate associations between exposure in two early life periods to severe levels of PM(2.5) from a mine fire, background PM(2.5), and primary and pharmaceutical care. METHODS: We linked records of births, general practitioner (GP) presentations and prescription dispensing for children born in the Latrobe Valley, Australia, 2012-2014, where a severe mine fire occurred in February-March 2014 in an area with otherwise low levels of ambient PM(2.5). We assigned modelled exposure estimates for fire-related (cumulative over the fire and peak 24-hour average) and annual ambient PM(2.5) to residential address. Associations with GP presentations and dispensing of prescribed medications in the first two years of life (exposure in utero) and in the two years post-fire (exposure in infancy) were estimated using two-pollutant quasi-Poisson regression models. RESULTS: Exposure in utero to fire-related PM(2.5) was associated with an increase in systemic steroid dispensing (Cumulative: IRR = 1.11, 95%CI = 1.00-1.24 per 240 μg/m(3); Peak: IRR = 1.15, 95%CI = 1.00-1.32 per 45 μg/m(3)), while exposure in infancy was associated with antibiotic dispensing (Cumulative: IRR = 1.05, 95%CI = 1.00-1.09; Peak: IRR = 1.06, 95%CI = 1.00-1.12). Exposure in infancy to ambient PM(2.5), despite relatively low levels from a global perspective (Median = 6.1 μg/m(3)), was associated with an increase in antibiotics (IRR = 1.10, 95%CI = 1.01-1.19 per 1.4 μg/m(3)) and in GP presentations (IRR = 1.05, 95%CI = 1.00-1.11), independently from exposure to the fire. We also observed differences in associations between sexes with GP presentations (stronger in girls) and steroid skin cream dispensing (stronger in boys). DISCUSSION: Severe medium-term concentrations of PM(2.5) were linked with increased pharmaceutical treatment for infections, while chronic low levels were associated with increased prescriptions dispensed for infections and primary care usage. Our findings also indicated differences between sexes.