Despite strong evidence supporting the use of angiotensin-converting enzyme inhibitors (ACED, beta-blockers, and spironolactone in heart failure, evidence suggests these drugs are under-used and under-dosed. The aim of the present study was to determine the impact of hospitalisation on heart failure pharmacotherapy in patients with congestive heart failure (CHF). A retrospective study was conducted, based on 300 consecutive admissions with the medical record diagnosis of heart failure, in each of seven grade one teaching hospitals. At admission, 49.5% of patients were treated with ACEI, 19.2% with beta-blockers and 8.1% with spironolactone. Twenty-six per cent of untreated patients started ACEI treatment during their hospital stay, and 9.4% started beta-blockers The main determinants of treatment with ACEI at discharge were a primary diagnosis of heart failure (odds ratio (OR) = 1.886) and the presence of a potential contraindication (high creatinine OR = 0.458, cough OR = 0.187, renal artery stenosis OR = 0.309). Patients were less likely to be discharged on beta-blockers if greater than 85 years of age (OR = 0.545), or there was mention of airways disease (OR = 0.347), asthma (OR = 0.238) or type 2 diabetes (OR = 0.721) on the medical record. Patients admitted by a cardiologist were more likely to be discharged on beta-blockers (OR = 3.207). Spironolactone was more likely used in patients with primary diagnosis of heart failure (OR = 1.549), aged less than 85 years (OR = 0.319), and/or admitted by a cardiologist (OR = 1.827). The substantial number of patients admitted to hospital with a secondary diagnosis of heart failure should be targeted for therapeutic optimisation.