In 2000, there were 89,740 notifications of communicable diseases in Australia collected by the National Notifiable Diseases Surveillance System (NNDSS). The number of notifications in 2000 was an increase of 5.9 per cent over those reported in 1999 (84,743) and the largest reporting year since the NNDSS commenced in 1991. Notifications in 2000 consisted of 28,341 bloodborne infections (32% of total), 24,319 sexually transmitted infections (27%), 21,303 gastrointestinal infections (24%), 6,617 vaccine preventable infections (7%), 6,069 vectorborne infections (7%), 2,121 other bacterial infections (legionellosis, meningococcal infection, leprosy and tuberculosis) (2%), 969 zoonotic infections (1%) and only one case of a quarantinable infection. Steep declines in some childhood vaccine preventable diseases such as Haemophilus influenzae type b, measles, mumps and rubella, continued in 2000. In contrast, notifications of pertussis and legionellosis increased sharply in the year. Notifications of bloodborne viral diseases (particularly hepatitis B and hepatitis C) and some sexually transmitted infections such as chlamydia, continue to increase in Australia. This report also summarises data on communicable diseases from other surveillance systems including the Laboratory Virology and Serology Surveillance Scheme (LabVISE) and sentinel general practitioner schemes. In addition this report comments on other important developments in communicable disease control in Australia in 2000.