Injecting drug use worldwide accounts for a high proportion of new Human Immunodeficiency Virus (HIV) infection, driving the national epidemics in many countries where HIV prevalence among injecting drug users (IDUs) is prominent. HIV testing started in Vietnam in 1988 and the first HIV case was detected in 1990. The epidemic has now concentrated among young IDUs in northern Vietnam. Hai Phong is one of the provinces located in the north of Vietnam which has become a high HIV prevalence province affecting young IDUs. The present research estimates HIV infection rates among IDUs in Hai Phong. It examines behavioural risk factors associated with HIV infection, sharing and condom use as well as highlighting drug and sex related transmission risks. The research has several stages including secondary analysis of national level behavioural survey data (2011) and qualitative exploratory research (2012). Each phase of the research supplements the others, in order to attain the research objectives and to address behavioural issues associated with the current epidemic.