Abstract: Context/Background: Evidence shows that addressing the unmet need for FP of vulnerable groups such as rural-to-urban migrants is another alternative to lowering fertility in developing countries. This study examines how migration affects unmet need in Cotonou. Data Source and Methods: We employed multinomial logistic regression using 2012 Benin Republic Demographic and Health Survey data concerning 827 married women aged | 5-49 years and residing in Cotonou. Findings: Findings show that recent migrants were less likely to have an unmet need than non-migrants. Then, earlier migrants and non-migrants had similar odds of unmet need. After adjusting for socioeconomic variables, the risks of unmet need for spacing and limiting among recent migrants decreased and increased, respectively, by 7%. Earlier migrants became significantly less likely to have an unmet need for spacing births than non-migrants. Conclusion: The odds of unmet need are lower among migrants than non-migrants, but complementary research on migrants’ fertility in Cotonou is necessary before any conclusion. Keywords: Migration; unmet need; family planning; Cotonou; Benin Republic