Available data suggest that the clinical outcomes of treatment, in the context of centres of excellence, externally funded projects or clinical trials, are very similar to those in industrialised countries. From about 1997, HIV care centres in 2 large Brazilian cities have recorded a significant decrease in the number of AIDS deaths, a reduction in the prevalence of major HIV related opportunistic infections and an overall decrease in the number of hospitalisations for HIV related illnesses. In the context of unregulated practice, the quality of care and the outcomes of treatment may be different but because such situations are difficult to evaluate, there is no information available.