Johne's disease was first diagnosed in an alpaca in Australia, from tissues collected at post-mortem, in February 1993. By June 1993, Johne's disease had been confirmed in another 3 alpacas that had shown chronic illthrift and had died. At autopsy, mesenteric lymph nodes were enlarged, fleshy and contained numerous acid fast bacilli. Three of clinical cases were between 12 and 18 months of age, one was 6 years old. All had a common property history. By December 1993, a further 3 subclinically infected alpacas had been identified from 1000 tested using conventional fecal culture. An enzyme-linked immunosorbent assay (ELISA) developed at the Victorian Institute of Animal Science for rapid identification of infected and non-infected alpacas is currently being evaluated. The test is a modification of the absorbed ELISA currently used for the diagnosis of bovine Johne's disease and uses a commercially available anti-llama conjugate. Testing to date suggests that the prevalence of Mycobacterium paratuberculosis infection in Australian alpacas is less than 1%. Extensive testing, using both the Elisa and fecal culture, is being used to identify infected herds. Restrictions on stock movements are preventing the spread of Johne's disease from those herds. Disease control on infected properties requires more information on the epidemiology of the disease in alpacas. The source of the infection has not been established.