The majority of the notifiable diseases recorded in the Northern Territory (NT) were sexually transmitted diseases (STDs) which accounted for 64%, a slight increase from 61% observed in 2005-06. In 2006-07, the most commonly recorded STDs were chlamydia (36%), trichomoniasis (32%), and gonococcal infection (26%). STDs were most prevalent in Central NT (41% of cases), followed by Darwin (15% of cases), Lower Top End (14% of cases) and East Arnhem (9% of cases).