The study aspires to assess the level of contribution of international organizations in fighting against HIV/AIDS in Zanzibar-Tanzania. The study was conducted in the Urban-West region of Unguja Zanzibar, using a descriptive survey based on cross-sectional design. The methods of data collection included focus group discussion, questionnaires, structured interview and documentary review. The study found that international organizations, which are governmental and non-governmental organizations, have been supporting HIV/AIDS Campaigns in Zanzibar through political, social, economic and medical assistance. The study found that there is high extent of availability of social assistance in respect to economic, political and medical assistance. Some obstacles that hinder the effectiveness of this assistance; are economic obstacles, social obstacles, medical obstacles and political obstacles. Finally, the study indicates that there are some possible measures to be taken so that to make effective use of the assistance.