Although civil society advocacy for health issues such as HIV transmission through injecting drug use is higher on the global health agenda than previously, its impact on national policy reform has been limited. In this paper we seek to understand why this is the case through an examination of civil society advocacy efforts to reform HIV/AIDS and drugs-related policies and their implementation in three former Soviet Union countries. In-depth semi-structured interviews were conducted in Georgia, Kyrgyzstan and Ukraine by national researchers with representatives from a sample of 49 civil society organizations (CSOs) and 22 national key informants. We found that Global Fund support resulted in the professionalization of CSOs, which increased confidence from government and increased CSO influence on policies relating to HIV/AIDS and illicit drugs. Interviewees also reported that the amount of funding for advocacy from the Global Fund was insufficient, indirect and often interrupted. CSOs were often in competition for Global Fund support, which caused resentment and limited collective action, further weakening capacity for effective advocacy.