ObjectivesTo estimate the risk of a first hospital admission for heart failure (HF) associated with the use of non-steroidal anti-inflammatory drugs (NSAIDs).MethodsCohort study with a nested case–control analysis based on the UK General Practice Research Database. Overall, 1396 cases of first hospital admission for non-fatal HF were identified (January 1997 to December 2000) and compared with a random sample of 5000 controls.ResultsThe incidence rate was 2.7/1000 person years. Prior clinical diagnosis of HF was the main independent risk factor triggering a first HF hospitalisation (relative risk 7.3, 95% confidence interval (CI) 6.1 to 8.8). The risk of a first hospital admission for HF associated with current use of NSAIDs was 1.3 (95% CI 1.1 to 1.6) after controlling for major confounding factors. No effects of dose and duration were found. The relative risk in current users of NSAIDs with prior HF was 8.6 (95% CI 5.3 to 13.8) compared with patients who did not use NSAIDs and without prior clinical diagnosis of HF.ConclusionUse of NSAIDs was associated with a small increase in risk of a first hospitalisation for HF. In patients with prior clinical diagnosis of HF, the use of NSAIDs may lead to worsening of pre-existing HF that triggers their hospital admission. This increased risk, although small, may result in considerable public health impact, particularly among the elderly.