Shigella infection rarely penetrates beyond the intestinal mucosa to cause bacteraemia. AIDS patients may be at increased risk. We investigated Shigella bacteraemia rates over a decade in a South African population with a high HIV prevalence and analysed presentation and outcome. A retrospective cohort analysis was performed for hospitalized patients for 2003-2006. The rates were compared to those for 1996-1998. Adult medical rates decreased from 0.195/1000 in 1996-1998 to 0.087/1000 admissions in 2003-2006, and paediatric rates were 0.807/1000 and 0.809/1000 admissions, respectively. Twenty patients were children (median age 7 months) and 14 were adults (median age 41 years). The main clinical presentations were acute (<or=7 days) diarrhoea [94% children and 27% adults (P=0.035)], chronic diarrhoea (27% adults) and pyrexia but no diarrhoea (36% adults and one child). Seventy-five percent of children were tested for HIV infection and 30% were found to be HIV-seropositive. The 10 adults tested were all HIV-positive. All children survived while 50% of adults died (P=0.002). Shigella flexneri caused 88% of cases. Shigella bacteraemia has not increased over a decade in a population with a high HIV burden but did seem to be HIV-related in adults. Children and adults differed in presentation and outcome.