Air pollution has been linked to the development and exacerbation of various health problems, including cardiovascular diseases such as heart failure. This project sought to spatially map the morbidity and mortality caused by heart failure within the county of Warwickshire, UK, to characterise and quantify any influence of air pollution on these risks. Data on air pollution, hospital admission for heart failure, and mortality within 105 Warwickshire county wards were collected from 2005 to 2013. Air pollution data included mono-nitrogen oxide (NO x ), sulphur dioxide (SO 2 ), particulate matter (PM), and benzene, which could then be united into a combined index. We used Bayesian geo-additive mixed models to map the spatial distribution of air pollution and heart failure data at the county level, accounting for county risk factors. During 2005–13 in Warwickshire, heart failure led to 5045 hospital admissions and 479 deaths. In multivariate analyses, presence of NO x , benzene, and index of multiple deprivation (IMD) score were consistently associated with risk of heart failure morbidity (posterior mean PM 3·35, 95% credible region 1·89–4·99 vs 31·9, 8·36–55·85 vs 0·02, 0·01–0·03). PM was negatively associated with the risk of heart failure morbidity (−12·93, −20·41 to −6·54) but no association with SO 2 was seen. Risk of heart failure mortality was higher in wards with a high NO x (4·30, 1·68–7·37) and in wards with more inhabitants older than 50 years (1·60, 0·47–2·92). PM was negatively associated with heart failure mortality (−14·69, −23·46 to −6·50). SO 2 , benzene, and IMD score were not associated with heart failure mortality. There was a striking variation in heart failure morbidity and mortality risk across wards, the highest risk being in the regions around Nuneaton and Bedworth (appendix). This study showed distinct spatial patterns in heart failure morbidity and mortality in Warwickshire, suggesting a potential role of air pollution beyond individual-level risk factors. Environmental factors should therefore be taken into account when considering the wider determinants of public health and the effect that changes in air pollution might have on the health of a population. This paper presents independent research supported by the National Institute for Health Research (NIHR) Collaborations for Leadership in Applied Health Research and Care West Midlands.