Few studies have reported the epidemiological characteristics and burden of severe cytomegalovirus (CMV) in the hospital setting. This study used data compiled by the Australian Institute of Health and Wealthfare(1) to examine the trends in hospital admissions due to CMV in different patient groups. As CMV disease mainly occurs in high-risk populations and almost always results in hospitalization, hospital data are an appropriate source of information on the epidemiology of clinically relevant disease. The study found that between 1993 and 2001 the average annual rate of hospital admissions where CMV was identified as the principal reason for admission amounted to 14.2 cases per 100,000 populations. This rate varied between 21.6 (1993/94) and 2.0 (2000/01) per 100,000 per year, and was always somewhat higher for men compared to women. The average annual incidence of children admitted to hospital with congenital CMV (principal and secondary diagnosis) in children aged 0-4, 5-9 and 10-14 years was 1.4, 1.3 and 0.4 per 100,000 respectively. Correlations with Human Immunodeficiency Virus (HIV), organ transplantation and other causes of immuno-suppression were also examined. The burden of severe CMV disease in Australia was found to be significant and comparable to other diseases for which national vaccination programs exist. As new vaccines for CMV may soon be available, understanding the pre-vaccination burden of CMV disease is useful for planning a vaccination program should a suitable vaccine be developed.