Abstract Objective: In Christchurch there is concern that winter air pollution, dominated by particulate matter (PM₁₀) from domestic heating, causes a local increase in cases of cardiorespiratory disease. Our aim was to investigate whether the particulate levels did influence emergency hospital admissions, and if so to what extent. Method: Air pollution and meteorological data was obtained from a Canterbury Regional Council monitoring station. Two local hospitals provided data on emergency admissions for both adults and children with cardiac and respiratory disorders. All data was obtained for the period from June 1988 to December 1998. Missing PM₁₀ data was interpolated from other known pollution values when necessary. The PM₁₀ data was compared to the admissions data using a time series analysis approach, with weather variables controlled for using a generalised additive model. Results: There was a significant association between PM₁₀ levels and cardiorespiratory admissions. For children and adults combined there was a 3.4% increase in respiratory admissions for every interquartile (14.8 µg/m³) increase in PM₁₀. In adults there was a 1.3 % increase in cardiac admissions for each interquartile increase in PM₁₀. There was no relationship between PM₁₀ levels and appendicitis, the condition that we selected to be our control. Conclusion: In Christchurch there is a significant relationship between particulate levels and the admissions for cardiac and respiratory illnesses. The size of the effect is comparable to other international studies, and the greatest impact is seen on the respiratory system.