Objective: To evaluate the proportion of patients hospitalised with acute coronary syndrome (ACS) in Australia and New Zealand who received optimal inpatient preventive care and to identify factors associated with preventive care. Methods: All patients hospitalised bi-nationally with ACS were identified between 14-27 May 2012. Optimal in-hospital preventive care was defined as having received lifestyle advice, referral to rehabilitation, and prescription of secondary prevention pharmacotherapies. Multilevel multivariable logistic regression was used to determine factors associated with receipt of optimal preventive care. Results: For the 2299 ACS survivors, mean (SD) age was 69 (13) years, 46% were referred to rehabilitation, 65% were discharged on sufficient preventive medications, and 27% received optimal preventive care. Diagnosis of ST elevation myocardial infarction (OR: 2.64 [95% CI: 1.88-3.71]; p<0.001) and non-ST elevation myocardial infarction (OR: 1.99 [95% CI: 1.52-2.61]; p<0.001) compared with a diagnosis of unstable angina, having a percutaneous coronary intervention (PCI) (OR: 4.71 [95% CI: 3.67-6.11]; p<0.001) or coronary bypass (OR: 2.10 [95% CI: 1.21 -3.60]; p=0.011) during the admission or history of hypertension (OR:1.36 [95% CI: 1.06-1.75]; p=0.017) were associated with greater exposure to preventive care. Age over 70 years (OR:0.53 [95% CI: 0.35-0.79]; p=0.002) or admission to a private hospital (OR:0.59 [95% CI: 0.42-0.84]; p=0.003) were associated with lower exposure to preventive care. Conclusions: Only one-quarter of ACS patients received optimal secondary prevention in-hospital. Patients with UA, who did not have PCI, were over 70 years or were admitted to a private hospital, were less likely to receive optimal care.