INTRODUCTION: Studies suggest no benefit from statins in heart failure (HF), but many individuals in primary care are prescribed statins before HF diagnosis. This study aimed to assess the effect of a statin prescription prior to HF diagnosis on survival in an incident HF population. MATERIAL AND METHODS: Cases of HF diagnosed between 1995 and 2004 in 315 UK primary care practices were identified from electronic case records and followed up for 2 years from diagnosis. Statin prescribing before and after HF diagnosis was assessed, and Cox regression was used to determine the contribution of statin treatment to survival. RESULTS: A total of 10,914 cases met the inclusion criteria of whom 20% (2185/10,914) were treated with a statin prior to HF diagnosis. Two per cent (191/8729) had an initial statin prescription following diagnosis. Cases prescribed a statin before heart failure diagnosis had a lower risk of death in the subsequent 2 years (hazard ratio 0.52; 95% confidence interval 0.39-0.68), after adjustment for confounders. DISCUSSION: Most people with heart failure prescribed statins in primary care commenced them prior to diagnosis and appeared to gain benefit, presumably through the effect of statins on cardiovascular co-morbidities. Primary care physicians should not discontinue prior statin treatment at the time of heart failure diagnosis.