The high rates of youth migration to urban and economic centers, in the context of persistent poverty and devastating HIV/AIDS burden, raises intricate social policy challenges in developing countries. This study examines patterns of internal migration and sexual initiation among Nigerian youths, using the 2003 Nigeria DHS data, descriptive statistics, Kaplan-Meier survival curves and discrete-time hazard regression models. Migrants generally show stronger association than non-migrants, and urban-urban migrants show the strongest independent association to early sexual initiation. These outcomes underscore that loss of social capital and exposure to sexually lenient urban environment increase youth's propensity to sexual engagement. Other significant covariates are age, gender, ethnic origin, education, independent living arrangement and formal employment. The findings highlight the inadequacy of policy perspectives that neglect complex contextual nuances across groups and the need to address limited livelihood opportunities that fuel youth migration to urban destinations.