Treatment with angiotensin converting enzyme inhibitors confers significant morbidity and mortality benefits in patients with heart failure, yet previous studies have repeatedly shown that these drugs are underutilised in general practice. To investigate why this is the case, we conducted an anonymous questionnaire survey of 515 general practitioners in the Nottingham Health District. The response rate was 60.2%. We found that although 39.3% of respondents underestimated the poor prognosis associated with heart failure, 98% were aware of the prognostic benefits conferred by angiotensin converting enzyme inhibitors. However, 46.3% of respondents expressed concern about the potential adverse effects associated with angiotensin converting enzyme inhibitors, the main fears being hypotension and renal impairment. General practitioners who were concerned about adverse effects were significantly less likely to have initiated an angiotensin converting enzyme inhibitor for heart failure than those who were not (P<0.01). Further research is needed to identify which patients can safely be commenced on angiotensin converting enzyme inhibitors in general practice. In the meantime, general practitioners should be encouraged to refer patients whenever they are concerned about initiating angiotensin converting enzyme inhibitors in the community.