Bocquier P, et al. - Via a matched cohort analysis of migration effects in Ouagadougou, Burkina Faso, the determine whether health outcomes as measured in urban populations highlighted local health risks and access to health services. Using the Ouagadougou Health and Demographic Surveillance System and a migrant follow-up survey, variations in health among matched non-migrants and outmigrants were estimated. Migrants who moved out of Ouagadougou were concluded to have greater mortality in comparison to non-migrants and migrants who moved to other Ouagadougou areas, after controlling for premigration health status. However, these impacts disappeared in the matched sample when controlled for all interactions among death determinants. Little evidence that migration led to greater mortality or worse health was exhibited by these and other outcomes. Hence, regardless of high migration intensity, health results as measured in the Ouagadougou population exhibited local health risks and access to health services. However, neither the hypothesis of the impact of health on migration nor the hypothesis of the negative impact of migration on health or survival was established.