RÉSUMÉ
There are gaps in evidence on whether unmet need for family planning has any implication for under-five mortality in Nigeria.This study utilized 2008 Nigeria Demographic and Health Survey data to examine the effect of unmet need on under-five mortality. Cox regression analysis was performed on 28,647 children born by a nationally-representative sample of 18,028 women within the five years preceding the survey. Findings indicated elevated risks of under-five death for children whose mothers had unmet need for spacing [Hazard ratio (HR): 1.60, confidence interval (CI) 1.37-1.86, p<0.001] and children whose mothers had unmet need for limiting (HR: 1.78, CI 1.48-2.15, p<0.001) compared to children whose mothers had met need. These findings were consistent after adjusting for the effects of factors that could confound the association. Findings of this study underscore the need to address the present level of unmet need for family planning in Nigeria, if the country would achieve meaningful reduction in under-five mortality.