Multinational Mining Companies in Tanzania have extended Corporate Social Responsibility to host communities in terms of health, roads construction, micro-finance, education, water supply projects and ‘others’ a category which comprises a bundle of petty projects. Mining Companies have used Corporate Social Responsibility to advance their profits and to gain legitimacy from the host communities. Moreover this study considered those motives and examined how Corporate Social Responsibility has impacted the reduction of HIV/AIDS prevalence to the treated group, that is, the communities which received Corporate Social Responsibility, in comparison with the control group, that is, those communities which didn't receive Corporate Social Responsibility. However, in this study there is no any basis to support the impact of Corporate Social Responsibility on reduction of HIV/AIDS prevalence in the treated group, that is, Mining Companies’ host communities. Necessary recommendations have as well been suggested for the way forward.