Aims: The aim of the study was to explore the long-term effect of allopurinol on mortality and cardiovascular hospitalisations in heart failure (HF) patients. Methods: This is a population-based cohort study using a record-linkage database in Tayside, Scotland. A total of 4785 HF patients (4260 non-users, 267 incident users and 258 prevalent users) were studied between 1993 and 2002. Results: Compared with non-users, low-dose users in the incident group had a significant increased risk of all-cause mortality, cardiovascular mortality and cardiovascular recurrence (adjusted HR, 1.60, 95%CI 1.26-2.03; 1.70, 1.29-2.23 and 1.44, 1.01-2.07). For the prevalent users, the adjusted HR were 1.27, 0.98-1.64; 1.43, 1.07-1.90 and 1.27, 0.91-1.76 respectively. There was no increased risk of outcome for high-dose users when compared with non-users (adjusted HR, 1.18, 0.84-1.66; 1.14, 0.76-1.71 and 1.36, 0.88-2.10 for the incident users, and 0.86, 0.64-1.15; 0.90, 0.64-1.26; and 1.27, 0.93-1.74 for the prevalent users respectively). High-dose allopurinol was associated with reduced risk of all-course mortality for prevalent users when compared with low-dose (adjusted HR 0.65, 95%CI 0.42-0.99). Conclusions: The prevalent high-dose allopurinol use had a lower risk of mortality than the prevalent low-dose use suggesting that allopurinol may be of benefit in HF patients.