To review and analyse the system effects of the Emergency Service Enhancement Program (ESEP): bonus payments made to public hospitals to improve access to care for patients attending emergency departments. A review of the first 3 years' performance data, obtained from the Victorian Emergency Department Minimum Dataset (VEMD). 21 public hospital emergency departments in Victoria, Australia (population 4.5 million), with about 700,000 patient attendances per year. The ESEP began in April 1995. The ESEP indicators of emergency department and inpatient bed access: occasions of "ambulance bypass" (emergency department unable to accept patients arriving by ambulance); emergency waiting times for Category 1, 2 and 3 patients (National Triage Scale) compared with agreed national performance thresholds; and "access block" (> 12 hours' waiting time in the emergency department before admission to hospital). The number of occasions of ambulance bypass per quarter decreased from 600 in 1994 to fewer than 100 in 1997 (P < 0.001). Despite an increased proportion of patient encounters in triage categories 1, 2 and 3 (31% v. 23%), zero waiting times for Category 1 patients were consistently adhered to, and adherence to waiting time thresholds for Category 2 and 3 patients improved significantly (P < 0.001, R2 = 0.74; and P < 0.035, R2 = 0.37, respectively), particularly for Category 2 patients. The number of patients waiting longer than 12 hours in emergency departments decreased non-significantly (P = 0.3, R2 = 0.1). Our results show that the ESEP has produced sustained improvements in all the indicators linked with bonus payments.