Migration is long standing phenomenon for Nepalese population. Migrated population are at higher risk of HIV infection. The objective of this article is to examine the risk factors that are associated with higher prevalence of HIV among migrant labours of Nepal. This review found that HIV prevalence, though decreased from 8.5% in 2002 to 1.1% in 2008, is still high among migrants. Multiple factors are associated with the risk of HIV prevalence in migrant group. The major determinants includes behavioural, social, environmental and health system capacity. Among migrants the rate of condom use was very low ( 17.7%) but visit to female sex workers and extramarital partners were found high. Peer pressure, low perceived risk of contracting disease, and less access to condom were some of the factors which hindered condom use. Availability of economically feasible service of female sex workers was another factor associated with high prevalence of the disease. Limited health system capacity is a cross cutting issue which has contributed in outnumbering this group from the main stream focus of HIV prevention effort. Unsafe sexual behaviour was the major determinant of HIV among migrants of Nepal. This review concludes that efforts of HIV prevention should be directed to migrants of rural areas to reduce the risk of spread of the disease.