As there was no empirical evidence of the effect of HIV/AIDS on pastoralism and pastoralist livelihoods, this study was commissioned by Ereto 1. This is also the first consolidated report on HIV/AIDS in Ngorongoro District, and presents and analyses the available data. It is learned that, despite relative low prevalence in the District, HIV/AIDS is spreading rapidly. The consequences of the spread of HIV/AIDS on pastoralist production systems, livelihoods and gender relations is analysed, and potential impacts presented. Making the distinction between 'awareness' and knowledge was identified as important, as although 100% of those interviewed had heard of (were aware of) HIV/AIDS, their 'knowledge' of the disease was limited and sketchy. For example, when asked how one gets HIV/AIDS, answers might include sharing a latrine, kissing, not praying, sharing clothes and toothbrushes, as well as some understanding it was transmitted through un-protected sex. The author identifies areas where communities can bring about change in practice and behaviour to cope with HIV/AIDS and its consequences, and provides proposals for possible future project intervention.