The rapid rate of rural-to-urban migration and the high vulnerability of migrants to HIV/AIDS and other sexually transmitted infections amplifies the need to devise effective, affordable, and culturally appropriate intervention strategies for urbanized migrant communities. To optimize the delivery and targeting of such interventions, studies are needed to examine changes in knowledge, beliefs, and behaviors that may occur during the process of settlement and integration into the host community. The principal goal of this study is to measure, as a function of time elapsed since migration, the changes in: 1) knowledge and awareness of HIV; 2) engagement in risk-related behaviors; and 3) willingness and barriers to use of HIV prevention and treatment services. The secondary goals are to: 1) explore the reasons migrants may feel unwilling to use services; and 2) explore the migrant-specific antecedents to high-risk behavior. Biological data will correlate prevalence of HIV/AIDS/STIs to the behavioral data. The hypothesis is that the knowledge/awareness of HIV and willingness to use services will increase as a function of time since migration, and engagement in high-risk behaviors will decrease. Based on these data, theories of the relationship between time since migration and HIV risk in rural-to-urban migrants will be developed, and appropriate intervention strategies for different phases of the migration process will be suggested. The results of this research should be instrumental in the development of theory-driven, empirically informed intervention strategies targeted to high-risk rural-to-urban migrants.